C# Dot Net

C# 2010 with Microsoft.Net Framework 4.0 Pragati Software Pvt. Ltd. www.pragatisoftware.com

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1

Index Module

Particulars

Page

Module 1

Getting Started

4

Module 2

Basic Language Constructs

15

Module 3

Class and Object

37

Module 4

Class Library

47

Module 5

Inheritance

59

Module 6

Exception Handling

75

Module 7

Other C# Features

85

Module 8

String, StringBuilder and Dateformats

99

Module 9

Collection classes

117

Module 10

Generics and Nullable Types

129

Module 11

Windows Form Control I

137

Module 12

File I/O

159

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2

Index

(Contd…)

Module 13

Working with DB

181

Module 14

Data Bound Controls

226

Module 15

DotNet Framework and Assembly

239

Module 16

Delegate

244

Module 17

Thread

253

Module 18

Introduction to Web Services

273

APPENDIX

Windows Form Control II

290

APPENDIX

Advance Thread

306

APPENDIX

Reflection

320

APPENDIX

Serialization

324

APPENDIX

Iterators

332

APPENDIX

SQL BULK copy

351

APPENDIX

Database Operations

353

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Module 1: Getting Started • Overview ¾ ¾ ¾ ¾

Introduction to C# Types of applications Understanding some terms: solution, project, Visual Studio IDE Writing, compiling and running a simple program

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4

Framework Version DLR C# 4.0

Code Contracts

VB 10

PLINQ

MEF

.Net Framework 4.0 Enhancement for WCF, WPF, WF C# 3.0 VB 9 LINQ AJAX

.Net Framework 3.5 WCF

WPF

WF

.Net Framework 3.0 C# 2.0

Card Space

VB 8.0

.Net Framework 2.0 CLR 4.0 Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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MEF : The Managed Extensibility Framework or MEF is a library for creating lightweight, extensible applications. It allows application developers to discover and use extensions with no configuration required. It also lets extension developers easily encapsulate code and avoid fragile hard dependencies. MEF not only allows extensions to be reused within applications, but across applications as well. DLR : The dynamic language runtime (DLR) is a runtime environment that adds a set of services for dynamic languages to the common language runtime (CLR). The DLR makes it easier to develop dynamic languages to run on the .NET Framework and to add dynamic features to statically typed languages.

.Net Framework

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.NET Framework is a common platform for designing, developing and deploying the various types of applications such as: Console Application, Windows Application, Web Based Application, Class Library Application, Web services, WCF, WPF, WF etc.. A developer can develop application by using any of the language which is compatible with .NET Framework. The languages compatible with .NET Framework are such as C#, VB, J#, VC++, F# etc. The Base class library provides a comprehensive set of facilities for application development. The .NET Framework provides a run-time environment called the Common Language Runtime. It runs the code and provides the services which makes the development process easier. Microsoft provides IDE as a Visual Studio to implement the .NET Framework. .NET Framework comes with redistributable installer that contains the Common Language Runtime and .NET Framework components which are necessary to run .NET Framework applications. The .NET Framework is available as a stand-alone executable file, Dotnetfx.exe. NOTE:Prior to .NET Framework for developing different types of applications different technologies were used. E.g. : For developing Console applications languages such as C/C++ was used. For developing Windows based applications VB was introduced by the Microsoft. For developing and designing web based applications, technologies such as HTML, DHTML, JavaScript, classic ASP were used. It means for developing specific type of application, one has to use different technologies.

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Types of Applications • • • • • • •

Console applications. Windows applications ASP.NET Web applications Class libraries Custom controls (User defined controls). Windows service Web Service

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We can create multiple kinds of applications such as: Console Applications: Applications that run on command prompt. Windows Applications: Desktop application using windows forms. ASP. Net Web Applications: Browser based applications i.e. Web sites. Class Library: Components basically are reusable piece of code that contains some business logic. Custom Controls: We can create our own controls from the existing controls either in windows or in web. Windows Services: We can create services that run in the background. Web Services: Web Services are web components. We can have a business logic available on the web that can be shared by people across the world.

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Features of C# • • • • • • • •

Object-oriented features Structured exception handling Powerful Windows based applications Building Web based applications Simple data access Multithreading Simplified deployment XML Web Services

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Features of C# C# is a very powerful language. It implements Rapid Application Development Tools for developing various kinds of application. Full Support for Object Oriented Programming. Structured Exception Handling helps create and maintain the program with robust error handlers. In this technique, we write a code which detects and traps the errors during execution and prevents application from inconsistent state. .NET provides an IDE to develop all kinds of applications such as Windows, Web, Console, AJAX based, Mobile etc into one environment using the languages that are supported by framework. Multithreading Capabilities.

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Creating a New Project

(Contd...) 1. Framework Version

2. Language

3. Application Template

4. Project Name 5. Project Location 6. Solution Name Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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Start Microsoft Visual Studio 2010. Click on File > New > Projects 1.Select from the drop down appropriate version of .NET Framework. 2.Choose the language C# from Left hand side project type.. 3.On the right hand side from the templates available, select Console Application. 4.Specify the project name. 5.Select the location to save the project. 6.Specify the name for solution.

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Solutions and Projects 1. Solution name

• A solution usually acts as a container for one or more projects • A project typically contains all the files required for the application.

2. Project name

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1. Solutions: A Visual Studio solution can include just one project or several projects built jointly by a development team. A complex application might require multiple solutions. 2. Projects: Visual Studio projects are used as containers within a solution to logically manage, build, and debug the items that comprise your application. The output of a project is usually an executable program (.exe) or a dynamic-link library (.dll) which known as Assembly.

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Writing the First Program namespace Module01 { class Program { static void Main(string[] args) { Console.WriteLine("Hello World..."); Console.ReadLine(); } } }

• Click on Debug -> Start to view the output.

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(Source code: C:\Training\Module01\Module01\Module01\Program.cs) Namespace is a logical collection of the types such as: class interface struct enum delegate In class Program we have Main() method which is known as entry point. Console is a class under System namespace which has a WriteLine() and ReadLine() as a method.

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Compilation Process in .NET Visual Basic

C#

J#

Compiler

Compiler

Compiler

Windows CLR

MAC CLR

JIT

JIT Managed code

CPU

CPU

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.Net framework supports various languages to develop the applications. A developer may write a code by using any of the language (VB, C#, J#, VC++, F#) which is compatible with .Net Framework. What happens when the code is written and compiled in .Net framework? Every language has its own language compiler. Very first the code is compiled by the language compiler and it produces a MSIL (Microsoft Intermediate Language) code. It is also known as “IL” code. This MSIL code is now sent to the CLR (Common Language Runtime). Once the MSIL code is sent to the CLR, only the code which is required during runtime is getting compiled into native machine code. This process is known as “JITing” and it is performed by a component known as “JITer” (Just in Time Compiler). Once the native machine code is produced it goes through under tight security policy which is known as “CASPOL” (Code-Access-Security-Policy). If this code is safe then only it is executed on CPU. This code is also known as “managed code”. Same process happens for the other OS also.

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Location of .exe file. 1. Location of .exe 2. Exe file

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.Exe is always stored at location : project folder\bin\debug.

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Components of CLR

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Class Loader : It loads all the Base Class Libraries required during execution of code. Type Verifier : Type verifier checks for the type compatibility. It is also known as “CTS”(Common Type System). The specification for the types are specified by “CLS” (Common Language Specification). Exception Manager : Exception manager manages the exception during runtime. JIT : Just-In-Time compiler produces native machine code which is required while runtime. Garbage Collector : It is also known as “Heap Manager” or “Auto memory manager”. It releases the memory by removing unused/out of scope objects. In invokes automatically. One can not predict about it’s invocation. Security Manager : Once the native machine code is produced, it is sent to the CPU for execution. This native machine code goes under tight security policy. This security policy is known as “CASPOL” . It is categorized into : 1) Code based Interface 2) Role based Interface. Thread Manager : Thread manager manages the multi-threading envt. COM Marshaller : While migrating from old COM application to .NET application ,the type compatibilty of COM applications with .NET types is marshalled by this component.

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Module 2. Basic Language Constructs • Overview ¾ Variables and data types ¾ Operators (arithmetic, relational, logical, assignment, conditional, etc.) ¾ Conditional statements

• if – else • switch ¾ Looping Constructs

• while • do….loop while() • for ¾ Arrays

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15

Data Types

(Contd…)

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The .NET platform provides Common Type System to all the supported languages. This means that all the languages must support the same data types as enforced by common language runtime. Data Types

Description

Example

object

The ultimate base type of all other types

object o = null;

string

String type; a string is a sequence of Unicode characters

string s = "hello";

sbyte

8-bit signed integral type

sbyte val = 12;

short

16-bit signed integral type

short val =12;

int

32-bit signed integral type

int val=12;

long 64-bit signed integral type long val2=34L;

long val1=12;

byte

8-bit unsigned integral type

ushort

16-bit unsigned integral

byte val1=12;

uint

32-bit unsigned integral type

uint val1=12; unit val2=34U;

ulong

64-bit unsigned integral type

ulong val1=12;

float

Single=precision floating point

float val = 1.23f;

ushort val1=12;

double Double-precision floating point type double val2=4.56D;

double val1=1.23;

bool

Boolean type; a bool value is either true or false

bool val1=true;

char

Character type; a char value is a Unicode character

char val1=‘h’;

decimal

Precise decimal type with 28 significant digits

decimal val = 1.23M;

Formatting Numeric Data C or c – Currency format D or d – double M or m – decimal F or f – float L or l - long

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Variable and Data type Program static void Main(string[ ] args) { double centigrade; double fahrenheit; centigrade = 33.3; fahrenheit = (centigrade * 9 / 5) + 32; Console.WriteLine("33.3 Centigrade = " + fahrenheit + " Fahrenheit."); Console.ReadLine(); }

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(Source code: Module02\Module02\01variable.cs) Variable Declaration int num; double salary, balance; string name;

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Common Type System (CTS)

Common Type System 

VC++

C# CLS Visual Basic.NET

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The Common Type System , is a part of the .net framework describes how the various data types must be declared, managed and used at runtime and plays a very crucial role for supporting cross language integration. Some of the most common functions it conducts are : 1.Type Safety, Cross language integration and high performance execution of code. 2.It has a set of rules that all .net compliant languages must follow so that the objects created in those languages can interact with each other . It supports the complete implementation of the programming languages. Common Language Specification (CLS) :

When you write code in one language and this code is then used by other programs that were developed in different languages, then that code should be CLS compliant, which simply means that it should abide by the rules specified in the CLS. The CLS describes features such as common data types for different languages. CLS compliance is important when software components that are created in one language will be used by other languages. The CLS is called as a subset of the CTS because it defines those set of rules that are a part of the CTS itself.

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CLS C# int i; string str; double dbl;

VB.NET Dim i as Integer Dim str as String Dim dbl as double

.NET Type System.Int32 i; System.String str; System.Double dbl;

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If one application written in C# and one application written in VB.NET wants to communicate with each other, how the communication will happen? In .NET if C# uses int to store numeric value which has a storage size 32 bits and VB.NET uses Integer to store numeric value which also has a storage size 32 bits. Then Common language specification specifies the common type compatible with both the types and produces a result as Int32.

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Named Constant static void Main(string[ ] args) { const float Pi = 3.14f; float radius, area; radius = 10.0f; area = Pi * radius * radius; Console.WriteLine("Area of circle = " + area.ToString()); Console.ReadLine(); }

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(Source code: Module02\Module02\02constant.cs) Named constants are created by declaring a variable with keyword const. Using a named constant can improve the readability of your code, as it becomes a form of documentation. Besides, since a named constant is defined in only one place in a program, if the value of the constant needs to be changed, it needs to be changed only in one place. Thus, use of named constants improves program maintenance also.

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Writing comments static void Main(string[ ] args) { /* variable declaration */ const float Pi = 3.14f; float Radius, Area; Radius = 10.0f; /* Calculation */ Area = Pi * Radius * Radius; //Printing Result Console.WriteLine("Area of circle = " + Area.ToString()); Console.ReadLine(); }

Comment

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comments can improve the readability (and thereby, maintainability) of source code. Single Line comment // text following // up to the end of the line is treated as a single line comment, and is ignored by the compiler. /* */ Similarly, any text between /* and the next */ is known as multi line comment, and is also ignored by the compiler. In C# you can add the contents by using short-cut keys (ctrl+E, C). And for uncommenting short-cut key used is (ctrl_E, U).

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Taking Input from the User Input window

static void Main(string[ ] args) { const float Pi = 3.14f; float Radius, Area; Console.Write("Enter the value for radius : "); Radius = float.Parse (Console.ReadLine()); Area = Pi * Radius * Radius; Console.WriteLine("Area = " + Area.ToString()); Console.ReadLine(); } Output window

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(Source code: (Source code: Module02\Module02\03userinput.cs) To take input from the user at the runtime we use Console.ReadLine() method and assigning the value to the variable “Radius”. When we take the input from the command line it is always taken as string type. The data type of the Radius variable is float, so we require to convert string type to float type. For that we are using the method Parse of the float type to convert string value to the float value.

When we print the value we are giving message and then we display the value. So every part of the Console.WriteLine() method has to be of a string type. So for printing we are converting the decimal value of area into string by using ToString() method.

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Operators Operator

Language Element

Arithmetic

+, –, *, /, %

Unary

++ , --

Assignment

=, +=, -=, *=,

Comparison

==, !=, , =

Concatenation

+

Logical operations

&&, ||

/=

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e.g. int num1=5, num2=10, num3; Arithmetic Operators : num1 + num2; num1 – num2; num1 * num2 ; num1 / num2; num1 % num2; Unary : pre-Increment/pre-decrement : ++num1 / --num1; post-Increment/post-decrement : num2++/num2 -Assignment : num3=num1 + num2; num1+=num2; Comparison : num3= num1==num2; It will return 1 (true) if both the numbers are equal or 0 (false) if numbers not equal. Concatenation : string str1 = “Hello “, str2 = “World”; Console.WriteLine(str1 + str2); Logical operations : && (Logical and) :num3=(num1 >5 && num2 5 || num2 Num2) Console.WriteLine("Num1 is greater the Num2"); else Console.WriteLine("Num2 is greater then Num1"); Console.ReadLine(); }

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The multiple if Structure Example static void Main(string[] args) { int a = 5, b = 6, c = 7, min, max; if (a >= b) { if (a >= c) { max = a; if (b >= c) { min = c; } else { min = b; } } else { max = c; min = b; } } else if (b >= c) { max = b; if (a >= c) { min = c; }

else { min = a; } } else { max = c; if (a >= b) { min = b; } else { min = a; } } Console.WriteLine("max={0} min={1}", max, min); }

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(Source code: Module02\Module02\04if.cs)

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The switch statement switch (expression) { case value: statements; break; case value: statements; break; default: statements; break; }

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To choose one option among the multiple choices switch-case statement is used.

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The switch statement Example case 7: static void Main(string[] args) case 8: { case 9: int month = 1; case 10: switch (month) Console.WriteLine("Monsoon { season"); case 11: break; case 12: default: case 1: Console.WriteLine(“Invalid month); case 2: Console.WriteLine("Winter Season"); } break; } case 3: case 4: case 5: case 6: Console.WriteLine("Summer season"); break; Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module02\Module02\06switch.cs)

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while loop while (condition) { statements; increment / decrement statement } static void Main(string[ ] args) { int num = 1; while (num Console Application. 2. Save as ABCCorporation. 3. From the solutions drop-down list select -> Add to Solution.

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Adding reference of dll to Application

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Menu options: 1.Click on Project -> Add reference . 2.From the dialogue box select projects tab -> select EmployeeLibrary.dll. (It the dll and application is in the same solution otherwise click on browse tab and select the required dll from the path).

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Creating a Test Application using EmployeeLibrary; class Program { static void Main(string[] args) { Employee employee = new Employee(1,"Trupti", 25000); double bonus=employee.CalcBonus(0.3); Console.WriteLine(“Bonus={0}”,bonus); Console.ReadLine(); } }

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(Source code : C:\Training\Module04\EmployeeLibrary\ABCCorporation\Program.cs)

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Set startup project

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Static field • Static field is used when we want to have values that are shared across all instances of a particular class. • Static fields and static constants enable this to happen by belonging to the class and not to the actual objects. • In your application, you can declare a variable and refer to it regardless of which instance of an object you are using. Such a variable is called static.

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Static field public class Employee { …… private static int Id=0; public Employee() { empId = 0; empName =“unknown”; salary = 0; } public Employee(int id,string Name, double sal) { ++id; this.empId = id; …… } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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Assignment • Create a class library project. Add Product class with following members: Product -productId ; -productName ; -unitPrice ; -Quantity + GetProducts(productname,unitprice,Quantity);

• productId must me auto incremented. • Display totalprice of product available Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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Module 5. Inheritance • Overview ¾ Object Oriented Concepts ¾ Bank Case Study ¾ Inheritance ¾ Constructor in extended classes ¾ Overriding methods ¾ Polymorphism ¾ Use of Sealed keyword ¾ Abstract class and method ¾ Declaring Interface ¾ Implementing Interface

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Object Oriented Concepts • • • •

Abstraction Encapsulation Inheritance Polymorphism

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Abstraction refers to the description of externally visible behavior of an object. Abstraction is used to describe what an object does, rather than how it does it. Encapsulation is a description of the internal data structures and internal implementation that give rise to this externally visible behavior. Encapsulation deals with how the object does it. Inheritance facilitates reusability of code. A new class can inherit all the properties and methods of another existing class. Polymorphism refers to the ability to hide many implementations behind the common interface. Using polymorphism, a single name may denote objects of many different classes.

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Bank Application • Create a class library project. • Save it as BankLibrary. • It will provide Business Logic of Banking Services.

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A BankAccount Class – the Super Class public class BankAccount { …. ; public BankAccount() { ….; } public BankAccount (string AccName, double Balance) { …. ; } public int AccNumber { get ; } public string AccName { get ; set ; } public double Balance { get ; set ; }

public double Withdraw(double amount) { …..; } public double Deposit(double amount) { ….. ; } }

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(Source code: C:\Training\Module05\BankLibrary\BankLibrary\BankAccount.cs)

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Inheritance Inheritance is a powerful feature of OOP. It provides following features: •Reusability •Easy maintenance of code. •Extendibility

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Inheritance Inheritance is a powerful feature of object-oriented programming languages. This refers to the ability of a class to inherit the fields and operations of another class, and extend these further. Inheritance can also be useful when two or more classes have some fields and operations in common. Instead of duplicating these common aspects in various classes, we can keep them in a base class, that other classes inherit from. For example, in a banking application, we may have a SavingsAccount class as well as a CurrentAccount class. Both these classes may have some common operations and fields, in addition to having their own specific fields and operations. Such common fields and operations can be kept in a common base class called BankAccount. The SavingsAccount and CurrentAccount classes can then inherit from the BankAccount class. In .NET, there is a class called Object. Every other class explicitly or implicitly inherits from the Object class. .Net allows single inheritance of the class.

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Access Specifiers Visibility / Access Specifier

private protected internal

public

protected internal

Same class

Yes

Yes

Yes

Yes

Yes

Derived class in same assembly

No

Yes

Yes

Yes

Yes

Other class

No

No

Yes

Yes

Yes

No

No

No

Yes

No

No

No

No

Yes

No

Other class in other assembly Derived class in other assembly

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The SavingsAccount Class – the Sub Class public class SavingsAccount : BankAccount { ….; static SavingsAccount() { …. ; } public SavingsAccount(string AccName,double Balance,bool IsSalaryAccount) :base(AccName,Balance) { ….. ; } public double CalculateInterest() { …. ; } }

Using Derived class object static void Main(string[ ] args) { SavingsAccount savingobject = new SavingsAccount(); …. ; }

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(Source code: Module04\Inheritance\SavingAccount.cs) An object of the SavingsAccount class would have all the fields other then private of its base class as well as the ones additionally defined within that class. Similarly, on an object of the SavingsAccount class, all the public and internal operations of the BankAccount class can be applied. In this program we have created the instance of SavingsAccount class, which is the derived class of the BankAccount class. All the members of the BankAccount class are created inside the memory of the SavingsAccount instance. It is calling the methods inherited from its base as well as of its own.

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Calling parent class constructor class BankAccount { public BankAccount(float balance) { …. ; } } class SavingsAccount : BankAccount { public SavingsAccount(float balance, bool IsSalaryAccount) : base(balance) { .. } }

Object

BankAccount

SavingsAccount

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(Source code: Module04\Inheritance\BankAccount.cs) (Source code: Module04\Inheritance\SavingAccount.cs) (Source code: Module04\Inheritance\Program.cs) A derived class must choose one of its super class constructors to invoke. The part of the object that is inherited from a super class must be initialized properly by the super class itself. The constructor of a derived class can invoke a base class's constructor using base keyword

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Overriding Methods •A method in sub class with the same signature as a super class has but with different implementation is known as method overriding. •Same signature means methods must have ¾same name. ¾same number of arguments ¾same type of arguments. ¾same access specifier •Keyword virtual is used in base class method definition. •Virtual indicates that this method can be overriden by sub class.

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A subclass can replace its super class's implementation of a method with one of its own. This is known as overriding a method. Both the signature and return type must be the same as the super class. In .Net by default method of super class cannot be overridden by sub class. For this sub class require permission from the super class Super class method should have keyword virtual and sub class method should have keyword override. virtual indicates that this method can be overridden by an identically named method in a derived class. virtual is the default setting for a method that itself overrides a base class method. Override keyword specifies that a property or method overrides a member inherited from a base class. This keyword indicates that method overrides an identically named method in a base class. The number and data types of the arguments, and the data type of the return value, must exactly match those of the base class procedure.

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Overriding Methods continued… class BankAccount { public virtual void Withdraw(float amount) { …. ; } } class SavingsAccount : BankAccount { public override void Withdraw(float amount) { ….. ; } public override ToString() { …. ; } }

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(Source code: Module04\Inheritance\BankAccount.cs) (Source code: Module04\Inheritance\SavingAccount.cs) (Source code: Module04\Inheritance\Program.cs)

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Polymorphism • Polymorphism is a Greek word which means “many-shaped”. • It has two distinct aspects: ¾ At run time object of inherited class may be treated as object of base class . ¾ Base classes may define and implement virtual methods and inherited classes may override these methods , which means inherited classes provide its own definition and implementation.

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Polymorphism class BankAccount { ….. ; public int AccountNumber { ….. ; } public float Balance { ….. ; } public BankAccount() { ….. ; } public BankAccount(float _balance) { ….. ; } public void Deposit(float amount) { ….. ; } public virtual void Withdraw(float amount) { … ; } } class SavingsAccount : BankAccount { ….. ; static SavingsAccount() { …. ;} public SavingsAccount() { ….. ; } public SavingsAccount(float balance, bool IsSalaryAccount) : base(balance) { ….. ; }

public float CalculateInterest() { ….. ; } public override void Withdraw(float amount) { …. ; } } class CurrentAccount : BankAccount { …… ; public CurrentAccount(float balance, float overdraftlimit) : base(balance) { ….. ; } public override void Withdraw(float amount) { ….. ; } } static void Main(string[ ] args) { BankAccount Bankref; Bankref = new SavingsAccount(7000,true); Bankref = new CurrentAccount(4000, 2000); }

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Preventing Overriding class BankAccount { public virtual void Withdraw(float amount) { …. ; } } class SavingsAccount : BankAccount { public sealed override void Withdraw(float amount) { ….. ; } }

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(Source code: Module04\SealedExample\BankAccount.cs) (Source code: Module04\SealedExample\SavingAccount.cs) (Source code: Module04\SealedExample\SubSavingAccount.cs) You can prevent subclasses from overriding the implementation of a method of a super class, by making it sealed. You can even make an entire class sealed, thereby preventing any extension of that class. All the methods of a sealed class are implicitly sealed. It can improve security. If a class is sealed, you know that nobody can extend it, and therefore, nobody can violate its contract. Similarly, if a method is sealed, you can rely on its implementation details. sealed is the default setting for a method that does not itself override a base class method.

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Preventing Inheritance sealed class SavingsAccount : BankAccount { } class SubSaving : SavingsAccount // compile time error { }

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Sealed classes are primarily used to prevent the inheritance. A sealed class can not be a base class. But it can be instantiated.

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Abstract Class •The abstract keyword enables you to create classes and class members solely for the purpose of inheritance. •The purpose of an abstract class is to provide a common definition of a base class that multiple derived classes can share. •An abstract class can not be instantiated. Abstract class public abstract class BankAccount { public abstract void Withdraw(float amount); } Abstract method

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You can mark a class as abstract, which means that the class cannot be instantiated. This way you can create a class that cannot have objects, but serves as a base for other subclasses. For example in a bank we can have account as either saving or current but we cannot have account type as a bank. The use of this class would be only to extend it to SavingsAccount and BankAccount class for reducing duplication of work and maintenance. The opposite of abstract is concrete; a concrete class can be instantiated. For example, Clerk, Executive and Manager would be concrete classes, extending the Employee class. For example, SavingsAccount and CurrentAccount would be concrete classes, extending the BankAccount.

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Interface •An interface contains only the signature of methods, delegates and events. •The implementation of the methods is done in the class which implements the interface. •An interface can inherit from one or more base interface. public interface Iinterest { float CaclulateInterest(float irate); }

Method signature

class SavingAccount : BankAccount, Iinterest { public float CaclulateInterest(float irate) { …. ; } }

Interface implementation

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An interface is a way to declare a type consisting only of abstract methods, Events or Properties. An interface provides a protocol binding to the classes that implement it. An interface cannot be instantiated. It consists of abstract methods, Events or Properties, i.e., it does not contain any implementation. An interface also cannot contain any variables.

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Module 6. Exceptions Handling • Overview ¾ ¾ ¾ ¾ ¾

What is Exception Handling? The “try-catch” Structure The finally Clause The throw Cause User Defined Exception

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What is an Exception Handling? • Error which occurs during runtime is known as Exception. • The mechanism to handle such errors during runtime is called as Exception Handling.

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try-catch-finally • C# provides 3 keywords to handle an Exception. ¾ try :- The try keyword is required. It lets the compiler know that you are attempting a normal flow of a program. ¾ catch :-During runtime if any exception occurs instead of letting the program crash the flow of the program can be transferred to cache section. catch block is always followed by try. ¾ finally :- This block executes always. It is optional to use finally.

• Syntax for try-catch-finally try { error prone code; } catch { statement for exception handling ; } finally { statement for clean up ; } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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Structured Exception Handling concept is introduced in .NET Framework. The System.Exception is the base class for all the exceptions in .NET. C# provides three keywords try, catch and finally to do exception handling. The try keyword encloses the statements that might throw an exception whereas the catch keyword is used to handle an exception if one exists. The finally clause can be used for doing any clean up process

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Understanding Exceptions static void Main(string[ ] args) { int num1, num2, ans; Exception occurs here num1 = 10; num2 = 0; ans = num1 / num2; Console.WriteLine("Answer = " + ans); Console.ReadLine(); }

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There are three types of errors which occurs in program, Syntax errors, run-time errors and logical errors. Exception handling is mechanism to detect and handle run time errors. .NET provides us Exception Handling techniques to overcome such situations. There are two types of exceptions: System Exception - Exceptions generated by CLR. Application Exception - Exceptions generated in application When we run the above code, it will get compile but at run time when control come to the line “ans = num1 \ num2", it will throw an exception. We require to manage this type of error which is known as Exception Handling

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Exception Handling Mechanism static void Main(string[ ] args) { …. ; try { int num1, num2, ans; num1 = 10; num2 = 0; ans = num1 / num2; Console.WriteLine("Answer = " + ans); } catch (DivideByZeroException ex) { Console.WriteLine(ex.Message); } }

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(Source code: Module05\ExceptionHandling\ExceptionHandling\Program1.cs) If any exception occurs inside the try block, the control transfers to the appropriate catch block and later to the finally block. The try block can exist either with one or more catch blocks or a finally block or with both catch and finally blocks. If there is no exception occurred inside the try block, the control directly transfers to finally block. The statements inside the finally block is executed always.

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Multiple Catch Block int num1, ans; int[ ] numarray = new int[1]; try { num1 = 10; numarray[0] = 5; ans = num1 / numarray[1]; Console.WriteLine("Answer = " + ans); } catch (DivideByZeroException ex) { …. ; } catch (IndexOutOfRangeException ex) { Console.WriteLine(ex.Message); } catch (Exception ex) { } finally { }

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(Source code: Module05\ExceptionHandling\ExceptionHandling\Program2.cs) A try block can throw multiple exceptions, which can be handled by using multiple catch blocks. We can use generalized Exception class to handle any type of runtime exception. Add the generalize catch block as the last catch block in the hierarchy otherwise at the compile time it will give an error. “A previous catch clause already catches all exceptions of this or of a super type ('System.Exception')” Some of the Exception classes are System.Exception System.DevideByZeroException System.NullReferenceException Syste.InvalidCastException System.IndexOutOfRangeException etc.

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finally •finally : Code in finally block is always executed. It contain clean up code to release the resources. int num1, ans; int[ ] numarray = new int[1]; try { …; } catch (DivideByZeroException ex) { …. ; } catch (IndexOutOfRangeException ex) { …; } finally { Console.WriteLine(“End of Main Block”); }

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Finally can be used in such cases where it’s needed to free-up the resources always. Finally block is optional.

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throw • throw : Exceptions can be explicitly generated by using a “throw “ keyword. int num1, num2, ans; num1 = 10, num2 = 0; if(num1/num2) { throw new DivideByZeroException(); }

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We can create our own exception by creating a class and inheriting it from the Exception base class. To throw the exception throw keyword is used throw keyword is used to raise an Exception. Sometimes it may happen that a method that is called might be getting an exception which is handled by the caller of that method. In such situation the throw keyword is used.

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User defined Exceptions •It is possible to create our own exception (user defined exception) classes. •System.Exception must be base class for all the exception classes. •In the constructor needs to define the steps which you want to perform.

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User Defined Exceptions class BalanceException : Exception { public BalanceException(string msg) :base(msg) { } } class SavingsAccount { ….. ; public SavingsAccount() { …. ; } public void Withdraw(float amount) { if ((balance - amount) > 500) balance -= amount; throw exception else throw new BalanceException("Not enough balance"); } }

User defined exception class static void Main() { SavingsAccount saving = new SavingsAccount(); try { saving.Withdraw(3000); } catch (BalanceException ex) { Console.WriteLine(ex.Message); } }

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(Source code: Module05\ExceptionHandling\ExceptionHandling\BalanceException.cs)

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Module 7. Other C# Features • Overview ¾ ¾ ¾ ¾ ¾ ¾ ¾ ¾ ¾

Structure enum Type casting Boxing Unboxing ref and out parameter Operator overloading Partial class Static class

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Structure •Structure is a generalization of the user defined data type. Used when a single variable is required to hold multiple types of data •Structure is a value type. struct Employee { ….. ; public Employee(int id, string name, string add, float sal) { ….. ; } public float AnnualSalary() { …. ; } } static void Main() { Employee emp1 = new Employee(101, “Smith", "Mumbai", 2000.00f); }

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(Source code: Module06\Module06\StructureExample.cs) Structure is a type like a class which we can define within the namespace. The members of a structure cannot be initialized within the structure declaration A structure can have instance constructors only if they take parameters A structure can have property or method Structure procedures cannot handle events A structure is not inheritable A structure can implement interface Structure •Structure is Value Types. (Stack memory) •By default all elements declared in structure are public. •Can have instance constructor only if they take parameters. •Unlike classes, structure can be instantiated without using a new operator. •Structure can not inherit from other structure or classes •Structure can implement interface

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enum •enum is a set of symbolic names that map to known numerical values. •enum is a set of named constant – collection of integer value. enum Months { Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec } class enumExample { static void Main() { Console.WriteLine(Months.Apr); Console.WriteLine((int)Months.Apr); } } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module06\Module06\enumExample.cs)

By default first enumerator value start from 0 and the value of each successive enumerator is increased by 1. enum Months { Jan=1, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec } You can assign integer value to the individual enumerator and the value of each successive enumerator is increased by 1. enum Months { Jan=1, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec }

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Type Casting • Converting value type to another value type OR

• Convert reference type to another reference type static void Main() { decimal number = 3.14M; int i = (int)number; Console.WriteLine("decimal value = {0}", number); Console.WriteLine("int i = {0}", i); Console.ReadLine(); }

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(Source code: Module06\Module06\TypecastingExample.cs)

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Boxing - Unboxing • Boxing is an implicit conversion of a value type to the reference type. • Unboxing is an explicit conversion from the reference type to a value type. static void Main() { int i = 10; //value type object obj = i; //boxing int j = (int)obj; //unboxing Console.WriteLine(i.ToString()); Console.WriteLine(obj.ToString()); Console.WriteLine(j.ToString()); Console.ReadLine(); } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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Value types are stored on the stack memory and Reference types are stored on the Heap memory.

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Ref Parameter class RefExample { static void Methodref(ref int i) { i = 100; } static void Main() { int number = 0; Console.WriteLine("Value of number = " + number.ToString()); Methodref(ref number); Console.WriteLine("Value of number = " + number.ToString()); Console.ReadLine(); } }

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(Source code: Module06\Module06\RefExample.cs) Ref parameter means argument passing by reference. Any changes to the parameter in the method will be applied to the variable when the control passes back to the calling method. To use the ref parameter, both the method and the calling method must explicitly use the ref keyword. An argument passed to a ref parameter must first be initialized.

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Out Parameter class OutExample { static void methodout(out int i, out string str) { i = 100; str="assigned value to out parameter"; } static void Main() { int number; string line; methodout(out number, out line); Console.WriteLine("number = " + number.ToString()); Console.WriteLine("line = " + line); Console.ReadLine(); } }

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(Source code: Module06\Module06\OutExample.cs) out parameter means argument passing by reference. Any changes to the parameter in the method will be applied to the variable when the control passes back to the calling method. To use the out parameter, both the method and the calling method must explicitly use the out keyword. An argument passed to an out parameter do not require to be initialized first. Although variable passed as out arguments do not have to be initialized before being passed, the calling method is required to assign a value before the method returns.

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Operator Overloading class OrderItem { private string productid; private Int32 quantity; private decimal unitprice; public string ProductID { get { return productid; } set { productid = value; } } public Int32 Quantity { get { return quantity; } set { quantity = value; } } public decimal UnitPrice { get { return unitprice; } set { unitprice = value; } } public decimal Total { get { return UnitPrice * Quantity; } } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module06\Module06\OperatorOverloadingExample.cs) Operator overloading means use of operator with an object. It gives better readability Operator overloading method always have public static access specifiers. Operator overloading always return a type and never be void. At least one operand must be of user defined type. Relational operators are overloaded in pairs only. The ref and out parameters are not allowed as arguments. Syntax public static return_type operator op ( argument list ) {}

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Operator Overloading

(Contd…)

public static OrderItem operator +(OrderItem Item1, OrderItem Item2) { if (Item1.ProductID != Item2.ProductID) { throw new Exception("You can only add OrderItems where the ProductID is the same for both objects"); } else if (Item1.UnitPrice != Item2.UnitPrice) { throw new Exception("You can only add OrderItems where the UnitPrice is the same for both objects"); } else { OrderItem item = new OrderItem(); item.ProductID = Item1.ProductID; item.Quantity = Item1.Quantity + Item2.Quantity; item.UnitPrice = Item1.UnitPrice; return item; } } } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module06\Module06\OperatorOverloadingExample.cs) Operators All binary operators can be overloaded +, -, *, /, %, &, | etc. All unary operators can be overloaded +, -, !, ~, ++, --, true, false All relational operators can be overloaded, but only in pairs ==, !=, > , =, , new, is, as, sizeof, Following operators are automatically overloaded when the respective binary operator is overloaded +=, -=, *=, /=

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Operator Overloading

(Contd…)

static void Main() { OrderItem Item1 = new OrderItem(); OrderItem Item2 = new OrderItem(); OrderItem Item3; try { Item1.ProductID = "1"; Item1.Quantity = 5; Item1.UnitPrice = 10; Item2.ProductID = "1"; Item2.Quantity = 4; Item2.UnitPrice = 10; Item3 = Item1 + Item2; Console.WriteLine(Item3.Total); } catch (Exception ex) { Console.WriteLine(ex.Message); } Console.ReadLine(); } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module06\Module06\OperatorOverloadingExample.cs)

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Partial Type partial class PartialTest { public void Method2(int i) { number = i; Console.WriteLine("number = " + number); } } partial class PartialTest { private int number; public int Method1(int i) { return i++; } } class PartialExample { static void Main() { PartialTest obj = new PartialTest(); Console.WriteLine(obj.Method1(100).ToString()); obj.Method2(10); Console.ReadLine(); } } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module06\Module06\PartialExample.cs) Partial class means class or structure definition can be split into multiple physical files. And all files are combined when the application is compiled. Can be used when working on a large project, allow multiple programmer to work on it simultaneously. Separate the business logic( user defined code) and system generated code in separate file. For example Windows Form Rules of partial class •All parts require to be define in same namespace. •Each part require to be available at compile time. •Must use the same access specifiers. (public, private,…) •If any single part is defined as abstract, then the whole class is abstract. •If any single part is sealed, then the whole class is sealed. •If any part declare a base type, then the whole class inherits that base class. •Parts can specify different interface, but the whole class implements all interfaces.

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Static class static class Temperature { public static double CelsiusToFahrenheit(double celsius) { //convert celsius to fahrenheit double Fahrenheit = (celsius * 9 / 5) + 32; return Fahrenheit; } public static double FahrenheitToCelsius(double fahrenheit) { double Celsius = (fahrenheit - 32) * 5 / 9; return Celsius; } }

class StaticExample { static void Main(){ double F, C; F= 100; C = 35; Console.WriteLine("{0} degree Celsius temperature in Fahrenheit: {1:F2}",C, Temperature.CelsiusToFahrenheit(C)); Console.WriteLine("{0} degree Fahrenhit temperature in Celsius: {1:F2}",F, Temperature.FahrenheitToCelsius(F)); Console.ReadLine(); } }

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(Source code: Module06\Module06\StaticExample.cs) Static class means class cannot be instantiated. It can contain only static members. And the class is sealed means cannot be inherited.

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Auto - Implemented Property class Person { public string Name { get; set; } public int Age { get; set; } }

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(Source code: Module06\Module06\ObjectInitializerExample.cs)

Auto implemented Property Auto-implemented properties make property-declaration more concise when no additional logic is required in the property accessor. Automatic properties allow you to avoid declaring manually a private field and write the get/set accessor -- instead the compiler create the private field and the default get/set accessor. You cannot write any validation for auto implemented properties. Auto-implemented properties must declare both a get and a set accessor. To create a readonly auto-implemented property, give it a private set accessor.

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Object Initializer class ObjectInitializerExample { static void Main() { Person pobj = new Person { Name = "Bhavana", Age = 18 }; Console.WriteLine("Name = " + pobj.Name); Console.WriteLine("Age = " + pobj.Age); Console.ReadLine(); } }

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(Source code: Module06\Module06\ObjectInitializerExample.cs) Object initializer allow you to include an initializer that specifies the initial values of the members of a newly created object. This enables you to combine declaration and initialization in one step.

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Module 8. String, StringBuilder, Dateformat • Overview ¾ ¾ ¾ ¾

Useful method of string class. StringBuilder class. Dateformats. Output formats.

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String Class methods • Various property and methods of string class • Property of string class • Length Gets the number of characters. string s= "welcome"; Console.WriteLine(s.Length);

//7

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(Source code: Module07\StringExample\StringExample\Program.cs) String is an immutable, means data cannot be changed. Whenever we try to change the data of string type, it is returning or creating brand new string object Escape Characters \’ – Single quote \” – double quote \\ - file paths \a – triggers system alert(beep) \n – new line \t – horizontal tab

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String class methods

(Contd…)

• Comparing Strings The compare method compares two strings and returns an integer value string s = "welcome"; string s1 = "Welcome"; int i; i = string.Compare(s, s1); Console.WriteLine(i); //-1 s = "welcome"; s1 = "welcome"; i = string.Compare(s, s1); Console.WriteLine(i); //0 s = "Welcome"; s1 = "welcome"; i = string.Compare(s, s1); Console.WriteLine(i); //+1 Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module07\StringExample\StringExample\Program.cs)

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String class methods

(Contd…)

• Concat the concat method concatenate two strings and returns a new string string s = "Hello"; string s1 = "World"; Console.WriteLine(string.Concat(s, s1));

//HelloWorid

• Copy Creates a new instance of string with the same value as a specified string string s = "Hello"; string s1; s1 = string.Copy(s); Console.WriteLine(s1); Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module07\StringExample\StringExample\Program.cs)

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String class methods

(Contd…)

• Ends with Determines whether the end of the string matches the specified string. Returns boolean result true or false. string s = "Welcome"; Console.WriteLine (s.EndsWith ("me")); // true

• Equals Determines whether two String objects have the same value. Returns Boolean result true or false. string s = "Welcome"; string s1= "welcome"; Console.WriteLine(s.Equals(s1)); //false

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(Source code: Module07\StringExample\StringExample\Program.cs)

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String class methods

(Contd…)

• IndexOf Return the index of the given String parameter in a Searched String. string s= "Welcome"; int i = s.IndexOf ("e"); //1 Console.WriteLine(i); i = s.IndexOf ("e", 2); //6 Console.WriteLine(i);

• LastIndexOf Returns the index position of the last occurrence of a specified String within the Searched String. string s= "Welcome"; int i = s.LastIndexOf ("e"); //6 Console.WriteLine(i); Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module07\StringExample\StringExample\Program.cs)

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String class methods

(Contd…)

• PadLeft Right-aligns the String, padding on the left with spaces or a specified character for a specified total length. • PadRight Left-aligns the String, padding on the right with spaces or a specified character, for a specified total length. string s= "Welcome"; Console.WriteLine(s.PadLeft(10, '*')); //***Welcome Console.WriteLine(s.PadRight(10, '*')); //Welcome***

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(Source code: Module07\StringExample\StringExample\Program.cs)

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String class methods

(Contd…)

• Remove Remove the characters from specified position in a given String. string s= "Welcome"; Console.WriteLine(s.Remove(3, 4)) ; // Wel

• Replace Replaces all occurrences of a specified character or String, with another specified character or string. string s = "Welcome"; Console.WriteLine (s.Replace ("e", "a")); // Walcoma

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(Source code: Module07\StringExample\StringExample\Program.cs)

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String class methods

(Contd…)

• StartWith Determines whether the beginning of the String matches the specified String parameter. Returns Boolean value true or false. string s = "Welcome"; Console.WriteLine (s.StartsWith ("We")); // true

• Substring Returns part of a string string s = "Welcome"; Console.WriteLine(s.Substring(3)); // come Console.WriteLine(s.Substring(3, 3)); // com

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(Source code: Module07\StringExample\StringExample\Program.cs)

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String class methods

(Contd…)

• ToLower Returns a String in lowercase • ToUpper Returns a copy of the String in uppercase. string s= "WELCOME"; Console.WriteLine (s.ToLower()); // welcome string s1 = "welcome"; Console.WriteLine (s1.ToUpper()); //WELCOME

• ToString Converts the value to a String type. Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module07\StringExample\StringExample\Program.cs)

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String class methods

(Contd…)

• Trim Removes all occurrences of a set of specified character from the beginning and end of the String.

• TrimEnd Removes all occurrences of a set of specified character from the end of the String.

• TrimStart Removes all occurrences of a set of specified character from the beginning of the String. String s= "-----------WELCOME-----------"; Console.WriteLine (s); Console.WriteLine (s.Trim('-')); //WELCOME Console.WriteLine (s.TrimEnd('-')); //-----------WELCOME Console.WriteLine (s.TrimStart('-')); //WELCOME---------Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module07\StringExample\StringExample\Program.cs)

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StringBuilder Class • The StringBuilder class represents a mutable string of characters. static void Main(string[ ] args) { StringBuilder builder = new StringBuilder("Hello wrold. "); Console.WriteLine(builder); builder.Append("This is class test."); Console.WriteLine(builder); builder.Insert(21, "StringBuilder "); Console.WriteLine(builder); builder.Remove(5, 6); Console.WriteLine(builder); builder.Replace(".", "!"); Console.WriteLine(builder); Console.WriteLine("Length = " + builder.Length); Console.ReadLine(); }

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(Source code: Module07\StringBuilderExample\StringBuilderExample\Program.cs) A string is a sequential collection of Unicode characters used to represent text. It is immutable because once specified the text can not be changed. There are methods to modify string but they will return a new string object with the changes made. These changes will not happen to the existing string object. The StringBuilder class represents a mutable string of characters. It's called mutable because it can be modified once it has been created by using Append, Insert, Remove, and Replace methods. The changes will happen to the existing StringBuilder object The StringBuilder class is defined in the System.Text namespace.

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Date formats Specifier

Description

Output

d

Short Date

8/4/2012

D

Long Date

8-Apr-12

t

Short Time

21:08

T

Long Time

21:08:59

f

Full date and time

4/8/2012 21:08

F

Full date and time (long)

4/8/2012 21:08

g

Default date and time

8/4/2012 21:08

G

Default date and time (long) 8/4/2012 21:08

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Date formats continued… Specifier

Description

Output

M

Day / Month

r

RFC1123 date

8-Apr Sun, 08 Apr 2012 21:08:59 GMT

s

Sortable date/time

2012-04-08T21:08:59

u

Universal time, local timezone 2012-04-08 21:08:59Z

Y

Month / Year

Apr-12

dd

Day

8

ddd

Short Day Name

Sun

dddd

Full Day Name

Sunday

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Date formats continued… Specifier

Description

Output

hh

2 digit hour

9

HH

2 digit hour (24 hour)

21

mm

2 digit minute

8

MM

Month

4

MMM

Short Month name

Apr

MMMM

Month name

April

ss

seconds

59

tt

AM/PM

PM

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Date formats continued… Specifier

Description

yy

2 digit year

yyyy

4 digit year seperator, e.g. {0:hh:mm:ss} seperator, e.g. {0:dd/MM/yyyy}

: /

Output 7 2012 9:08:59 8/4/2012

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Date formats continued… DateTime time = DateTime.Now; string format = "ddd"+" "+"dd-MMM-yyyy"; Console.WriteLine(time.ToString(format)); Console.ReadLine();

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Output formats Character C or c

Description

Examples

Output

Currency

Console.Write("{0:C}", 2.5);

$2.50

D or d

Decimal

Console.Write("{0:C}", -2.5); Console.Write("{0:D5}", 25);

($2.50) 25

E or e F or f

Scientific Fixed-point

Console.Write("{0:E}", 250000); Console.Write("{0:F2}", 25); Console.Write("{0:F0}", 25);

2.50E+05 25 25

G or g N or n

General Number

Console.Write("{0:G}", 2.5); 2.5 Console.Write("{0:N}", 2500000); 2,500,000.00

X or x

Hexadecimal Console.Write("{0:X}", 250); Console.Write("{0:X}", 0xffff);

FA FFFF

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116

Module 9. Collections • Overview ¾ ¾ ¾ ¾

System.Collections Namespace. ArrayList HashTable Collection Initializer

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Collection Classes • • • •

A collection is a set of objects. Using collection we can organize and manipulate the objects. Can keep the track of objects. The System.Collection namespace contains the different types of collection classes, such as Stack, Queue, ArrayList, HashTable, etc.

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ArrayList • • • • •

ArrayList is a collection of element of different types. It increases the size of the storage location as required. It stores the value as object. It represents dynamically sized array of objects. It is contained in the namespace System.Collections;

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ArrayList Example Using System.Collection; static void Main(string[ ] args) { ArrayList countryList = new ArrayList(); countryList.Add("India"); Console.WriteLine("Total items = " + countryList.Count.ToString()); for (int i = 0; i < countryList.Count; i++) { Console.WriteLine(countryList[i].ToString()); } //insert value countryList.Insert(1, "France"); Console.WriteLine("\n-------print specific item form the arraylist object-------\n"); Console.WriteLine(countryList[2].ToString()); }

//reverse countryList.Reverse(); //sort countryList.Sort(); //RemoveAt() countryList.RemoveAt(2); //Clear() countryList.Clear(); }

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(Source code: Module07\CollectionExample\CollectionExample\ArrayListExample.cs) ArrayList is the collection of elements of different type Elements in this collection can be accessed using an integer index. Indexes in this collection are zerobased.

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HashTable • HashTable object contains Items in key and value pair. • Keys are used as indexes. • Values can be searched by using keys.

MH

Maharashtra

GA

Goa

GJ

Gujrat

TN

Tamilnadu

AP

Andra pradesh

RJ

Rajasthan

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HashTable Example static void Main() { Hashtable hashlist = new Hashtable(); hashlist.Add("txt", "notepad.exe"); hashlist.Add("bmp", "paint.exe"); hashlist.Add("rtf", "wrodpad.exe"); // The Add method throws an exception if the new key is already in the hash table. try { hashlist.Add("txt", "winword.exe"); } catch { Console.WriteLine("An element with Key txt already exists."); }

Console.WriteLine("\n------------------------------\n"); //DictionaryEntry - Defines a dictionary key/value pair that can be set or retrieved. foreach (DictionaryEntry de in hashlist) { Console.WriteLine("Key = {0}, Value = {1}", de.Key, de.Value); } Console.WriteLine("\n------------------------------\n"); //Printing the value of the specific key Console.WriteLine("For key = rtf, value = {0}.", hashlist["rtf"]); Console.ReadLine(); }

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(Source code: Module07\CollectionExample\CollectionExample\HashTableExample.cs) HashTable represents a collection of key/value pairs that are organized based on the hash code of the key.

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Stack • Stack represents last-in-first-out (LIFO) . • You may assume kitchen dish stack. You can pull out a top most dish which is kept in stack very last. • It simply consists of non-generic collection of objects. pop

push

5 4 3 2 1 0

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Stack Example static void Main() { Stack stackobj = new Stack(); stackobj.Push("Hello"); stackobj.Push("Stack"); stackobj.Push("class"); stackobj.Push("example"); Console.WriteLine("Count = " + stackobj.Count.ToString()); Console.WriteLine("\n------------------\n"); foreach (Object obj in stackobj) { Console.WriteLine(obj.ToString()); }

Console.WriteLine("\n---------Top Element- peek method---------\n"); Console.WriteLine(stackobj.Peek()); Console.WriteLine("\n---------Top Element- pop method---------\n"); Console.WriteLine(stackobj.Pop()); Console.WriteLine("\n---------count---------\n"); Console.WriteLine("Count = " + stackobj.Count.ToString()); foreach (Object obj in stackobj) { Console.WriteLine(obj.ToString()); } Console.ReadLine(); }

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Queue • Queue represents first-in-first-out (FIFO) . • We can Enqueue (add) items in queue. • We can Dequeue (remove) items from queue.

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Queue Class static void Main() { Queue queueobj = new Queue(); queueobj.Enqueue("Hello"); queueobj.Enqueue("Queue"); queueobj.Enqueue("class"); queueobj.Enqueue("example"); Console.WriteLine("Count = " + queueobj.Count.ToString()); foreach (Object obj in queueobj) { Console.WriteLine(obj.ToString()); } Console.WriteLine("\n---------Top Element- ---------\n“, queueobj.Dequeue()); Console.WriteLine("\n---------count----------\n“, queueobj.Count.ToString()); foreach (Object obj in queueobj) { Console.WriteLine(obj.ToString()); } Console.ReadLine(); } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module07\CollectionExample\CollectionExample\QueueExample.cs)

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Linked List • A Linked list is a data structure consisting of group nodes which together represents a sequence.

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Collection Initializer • Able to give values to collections in a concise and compact manner static void Main() { ArrayList countryList = new ArrayList { "India", "Usa", "Japan" }; for (int i = 0; i < countryList.Count; i++) { Console.WriteLine(countryList[i].ToString()); } Console.ReadLine(); }

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(Source code: Module07\CollectionExample\CollectionExample\CollectionInitializerExample.cs)

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Module 10. Generics and Nullable Types • Overview ¾ ¾ ¾ ¾

Limitations of Collection Classes Understanding Generics Advantages of generics over collection Nullable Types

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Limitation of Collection Classes class Person { for (int i = 0; i < list.Count; i++) { list[i]. //error 1 string name, address; public Person(string name, string address) { this.name = name; this.address = address; } //error 2 public void Display(){ ((Person)list[i]).Display(); } Console.WriteLine ("Name = " + name); Console.WriteLine("Address = " + address); } } static void Main(string[] args) { ArrayList list = new ArrayList(); //error 3 list.Add(new Person("Bhavana", "Mumbai")); int temp =int.Parse( list[0].ToString()); } list.Add(new Person("Vishal", "Mumbai")); list.Add("Krishna");

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Whenever we store any data to the collection class object they are always maintained as Object type. Because of this it is possible that we can store different type of data in collection object. This feature one way is advantageous that we can store different types of value in collection, but this feature also have some disadvantages Error 1 We are storing different type of values in the ArrayList object We have added the object of Person class which is user defined type. While retrieving the members of the list object we typed list[i]. Which gives public member of the Object class only and it will not give the public member which you have defined in Person class. Error 2 You require to explicitly typecast the member. After typecasting it will give the public member of the Person class. But it will give an error at the run time when in the for loop when we try to retrieve the third item which is not of the Person type. Error 3 At the compilation time it allows us to convent any member of the ArrayList to int type or any other type. But at the run time when it require to assign the value of user defined type to an int type it will give an error.

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Why Generics? • In the earlier code example two major issues were faced as follows: ¾ Boxing and unboxing overhead : Boxing and unboxing operations lead to performance overhead since it involves dynamic memory allocation and runtime type check. ¾ No strong type data at compilation time : The earlier code is technically correct. Error will be not be thrown at compile time. But when the code is executed it will throw an exception InvalidCastException.

• Generics has solution for these limitations.

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Generics • Type Safety -- Generic types enforce type compliance at compile-time, and not run-time (as in the case of using Object). This reduces the chances of data-type conflict during run-time • Performance -- The data types to be used in a Generic class are determined at compile-time, hence there is no need to perform type casting during run-time, which is a computationally costly process. • Code reuse -- Since you only need to write the class once and customize it to use with the various data types, there is a substantial amount of code-reuse.

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Comparison between Generic, Collection and Array •To define an array, we have to give the fix size. The size can’t be dynamically increased. Every time reallocation of memory happens. •Collections are dynamic. To store or retrieve a value, it performs boxing and un-boxing which affects performance considerably. •Whereas generics are type safe. While defining it we have to provide a type. No other type value can be stored.

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Generics List Collection static void Main() { List liststr = new List(); liststr.Add("Vishal"); liststr.Add("Amit"); //liststr.Add(new Person("Pankaj", "Mumbai")); //compile time error for (int i = 0; i < liststr.Count; i++) { Console.WriteLine(liststr[i]); } Console.WriteLine("\n-------------------------------\n"); List listperson = new List(); listperson.Add(new Person("Bhavana", "Mumbai")); listperson.Add(new Person("Pankaj", "Mumbai")); for (int i = 0; i < listperson.Count; i++) { listperson[i].Display(); } Console.ReadLine(); } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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Generic Dictionary collection class Customers { …. public Customers(string Name, string Location) { ….. } public int CustId { get ; } public string CustName { get; set; } public string CustLocation {get; set; } public void displayCust() { … } } static void Main(string[] args) { Dictionary customerDictionary = new Dictionary(); Customers customer3 = new Customers("Anju", "Borivali"); Customers customer4 = new Customers(“Amit", "Kalyan"); foreach (KeyValuePair custKeyValue in customerDictionary) { Console.WriteLine( custKeyValue.Key, custKeyValue.Value.CustName, custKeyValue.Value.CustLocation); } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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Generic Dictionary collection stores information into key/value pair. There is a non generic collection HashTable which also stores the information into key/value pair. But it stores data of type object.

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Creating our own Generic Classes class GenericClass { T value1, value2; public UserdefinedGeneric(T val1, T val2) { value1 = val1; value2 = val2; } public void Swap() { T temp = value1; value1 = value2; value2 = temp; Console.WriteLine(value1 + " “ + value2); } }

static void Main(string[] args) { UserdefinedGeneric obj1 = new UserdefinedGeneric("Trupti", “Hello"); obj1.Swap(); UserdefinedGeneric obj2 = new UserdefinedGeneric(“25", “50"); obj2.Swap();

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Generic is a technique with which you can delay the specification of the type of one or more programming elements in a class or a method ,until the time of the usage of that class or method. With generics instead of specifying the data type of the parameters, you define labels, which can later be replaced by the data type that the user specifies at the time of using the generic method or class Generic is a type parameter, which allows to design a class or method where the value of the type is specified at the time of instantiating class or usage of a method.

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Nullable Type static void Main() { int number1 = 10; Nullable number2 = null; int? number3 = null; try { Console.WriteLine("number1 = " + number1.ToString()); Console.WriteLine("number2 = " + number2.Value); Console.WriteLine("number3 = " + number3.ToString()); Console.WriteLine("\n------------------------------\n"); if (number2.HasValue == true) Console.WriteLine("number2 = " + number2.Value); else Console.WriteLine("Null value"); Console.WriteLine("\n------arithmatic operation with nullable type--------\n"); Console.WriteLine(number1 + number2.GetValueOrDefault(0)); number2 = 100; Console.WriteLine(number1 + number2.GetValueOrDefault(0)); } catch (Exception ex) { Console.WriteLine(ex.Message); } Console.ReadLine(); Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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Nullable type One of the primary differences between value types such as int or structures and reference types such as string is that reference types support a null value. That is to say, a reference type variable can contain the value null, which means that the variable doesn't actually refer to a value. In contrast, a value type variable always contains a value. An int variable always contains a value, even if that number is zero. Nullable type adds nullability to any value type.

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Module 11. Windows Form - I • Overview ¾ ¾ ¾ ¾ ¾

Introduction to Window Forms IDE Creating forms with controls Responding to form events Using basic controls (e.g. Label, TextBox, Button, etc.) Anchor and Dock Properties

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137

Visual Studio IDE ToolBox

Form Design View

Solution Explorer

Property Window

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GUI application helps us to create user interface. A well designed interface makes the application more users friendly. In a windows based application, user interface is accomplished with windows Forms and controls. Windows form is a base container for user interface. A control is an object that can be drawn on to the Form to enable or enhance user interaction with the application. Examples of these control, TextBox, Button, Label, Radio Button etc. All these Windows Controls are based on the Control class, which is the base class for all controls. To create GUI application, Start Visual Studio .Net, from Project Window select Template type as Windows Application. System will open visual studio .net IDE which include Form Designer, Solution Explorer, Property window, toolbox etc.

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Introduction to Controls Label

TextBox MultiLine TextBox

RadioButton ComboBox

ListBox

Button

CheckBox

GroupBox

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Form is a base unit on which we can place the controls. Every controls including Form will have properties, methods and events. Forms properties Text – Value to be display in the title bar WindowState – Initial visual state of a form

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Label Example • Display dynamic time.

private void timer1_Tick(object sender, EventArgs e) { lbldatetime.Text = DateTime.Now.ToString(); } private void DynamicTime_Load(object sender, EventArgs e) { lbldatetime.Text = DateTime.Now.ToString(); } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module10\WinForm1\WinForm1\DynamicTime.cs) Label Properties Name – lbldatetime Text – empty Timer control from the component tab Properties Enable – True Interval – 1000

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MessageBox Class • Use to display informative message to the user and can take user confirmation. •

MessageBox.Show("Welcome to GUI Application");

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(Source code: Module10\WinForm1\WinForm1\Form1.cs) Static method MessageBox.show() is used to accept the message, title, buttons and icon as parameters. Only message is the compulsory parameter.

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Login Form Example

public partial class LoginForm : Form { int count = 0; public LoginForm() { InitializeComponent(); } private void btncancel_Click(object sender, EventArgs e) { this.Close(); } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module10\WinForm1\WinForm1\LoginForm.cs) Design a form which accept user name and password. Check username as “pragati” and password as “admin”. If username and password are correct then show the Win Form welcome else display the proper error message in the message box. Give three chance to write the correct username and password else display appropriate message and close the application. Label Display static text from providing information. Properties Name - Control Name Text – Value to be displayed AutoSize – Allow automatic resizing according to the txt length

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Login Form Example

(Contd…)

private void btnsubmit_Click(object sender, EventArgs e) { if (txtusername.Text == "pragati" && txtpwd.Text == "admin") { Welcome frm = new Welcome(); this.Hide(); frm.Show(); } else { MessageBox.Show("Invalid username or password. Please provide the correct value", "Login"); count = count + 1; txtusername.Clear(); txtpwd.Clear(); txtusername.Focus(); } if (count == 3) { MessageBox.Show("Sorry! Please try again", "Login"); this.Close(); } } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module10\WinForm1\WinForm1\LoginForm.cs) TextBox Display text to the user and accept the input from the user. Properties Name – Control Name Text – Display or accept the text Multiline – convert single line textbox into multi line textbox PasswordChar – set a character that acts as a placeholder for the characters. Button Perform an action Properties Name - Control name Text – Value to be displayed AutoSize – Controls automatically size itself to fit its content. Image – Image to be displayed

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Welcome Form

private void btnclose_Click(object sender, EventArgs e) { Application.Exit(); }

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(Source code: Module10\WinForm1\WinForm1\Welcome.cs) This.Close() will close the individual form while Application.Exit() method will close all the form which are loaded in memory for that application.

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ComboBox Example

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(Source code: Module10\WinForm1\WinForm1\ComboBoxExample.cs) Select your qualification and computer skills from the list given below. Select the country from the combo dropdown. If users want he/she can add the country name in the combo dropdown. While adding the new data keep check that no duplication allowed. Same time if user wants he/she can delete the country name from the list. ComboBox Display a drop down list of items, from which user can select any one item. Properties Name – Control name Text – Selected text from the list Items – Collection of the items to be displayed in drop down DropdownStyle – Appearance and functionality of combo box Add some country name in combo box at design time by using Items property. We can also add data dynamically.

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ComboBox Example

(Contd…)

private void btnadd_Click(object sender, EventArgs e) { int i, flag =0; for( i=0;i Add New Item ¾ From left hand side select “General” option and from the write hand side select “Application Configuration File”. ¾ Do not change the name of this file. ¾ Click on “Add” button to add the file in your project.

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•Config is a XML file. •if you have to change server name ,database name etc in connection string then you have to make changes in only .config file and not on each and every Forms. •you can also add more than one connection string in config file. •To access the connection string from the config file, first you have to add the reference to the System.Configuration namespace in your project. •use the System.Configuration namespace in every C# files, where you want to use the connection string from the config file.

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Configuring Connection String in .config File (contd…) • Write the connection string in the confilg file within connectionStrings element

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190

Using Connection String in C# file using System.Data.SqlClient; using System.Configuration; string connstr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString; SqlConnection conn = new SqlConnection(connstr);

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191

Display Data using Connected Architecture

string connstr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString; SqlConnection conn = new SqlConnection(connstr); string sql = "select * from categories"; SqlCommand cmd = new SqlCommand(sql, conn); conn.Open(); SqlDataReader reader = cmd.ExecuteReader(); DataTable table = new DataTable(); table.Load(reader); conn.Close(); dataGridView1.DataSource = table; Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module12\DatabaseApplication\DatabaseApplication\02Connected.cs)

192

Apply Filter on DataSet

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(Source code: Module12\DatabaseApplication\DatabaseApplication\03Filter.cs) DataSet data is the in memory data. After we retrive the data in dataset, we can apply the filter on it and display the specific data to the users. For this there are 2 methods 1] Select() method of the DataTable class and 2] DataView class object with RowFilter Property

193

Apply Filter on DataSet

(Contd…)

• Declare the 2 class level variable int catid = 0; DataSet ds;

• Form Load Event string connstr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString; SqlConnection conn = new SqlConnection(connstr); SqlDataAdapter adp = new SqlDataAdapter("select * from Categories", conn); ds = new DataSet(); adp.Fill(ds, "Categories"); adp = new SqlDataAdapter("Select * from Products", conn); adp.Fill(ds, "Products"); lstcategory.DisplayMember = ds.Tables["Categories"].Columns["CategoryName"].ToString(); lstcategory.ValueMember = ds.Tables["Categories"].Columns["CategoryID"].ToString(); lstcategory.DataSource = ds.Tables["Categories"]; Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module12\DatabaseApplication\DatabaseApplication\03Filter.cs)

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Apply Filter on DataSet •

(Contd…)

ListBox SelectedIndexChanged Event

if (lstcategory.SelectedIndex >0 && lstcategory.SelectedValue != null) { catid = (int) lstcategory.SelectedValue ; }

•

View Button Click Event

DataView view = ds.Tables["Products"].DefaultView; view.RowFilter="categoryid=" + catid; dataGridView1.DataSource = view;

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195

Apply Filter on DataSet – DataTable Select() Method • select button click event lstselect.Items.Clear(); DataRow[] row = ds.Tables["Products"].Select("categoryid=" + catid); if (row.Length > 0) { for (int i = 0; i < row.Length; i++) { lstselect.Items.Add(row[i]["productName"]); } }

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(Source code: Module12\DatabaseApplication\DatabaseApplication\03Filter.cs)

196

Insert data using Connected Architecture

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197

Insert data using Connected Architecture Code string connstr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString; SqlConnection conn = new SqlConnection(connstr); string sql = "Insert into products (productname, unitprice) values (@pname, @price)"; SqlCommand cmd = new SqlCommand(sql, conn); cmd.Parameters.AddWithValue("@pname", txtpname.Text); cmd.Parameters.AddWithValue("price", decimal.Parse(txtup.Text)); conn.Open(); int feedback = cmd.ExecuteNonQuery(); conn.Close(); MessageBox.Show(feedback + " record inserted"); cmd.CommandText = "select productid, productname, unitprice from products where productid >77"; conn.Open(); SqlDataReader reader = cmd.ExecuteReader(); DataTable table = new DataTable(); table.Load(reader); conn.Close(); dataGridView1.DataSource = table; Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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198

Stored Procedure

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(Source code: Module12\DatabaseApplication\DatabaseApplication\08spin.cs)

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Stored Procedure

(Contd…)

• Write the following stored procedure in the MS SQL Server create proc InsertData (@prodname varchar(20), @unitprice numeric(10,2)) as begin transaction insert into products (productname, unitprice) values (@prodname, @unitprice) Commit transaction

• Code for the Insert Button Click string connstr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString; SqlConnection conn = new SqlConnection(connstr);

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(Source code: Module12\DatabaseApplication\DatabaseApplication\08spin.cs)

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Stored Procedure

(Contd…)

SqlCommand cmd = new SqlCommand ("Insertdata", conn); cmd.CommandType = CommandType.StoredProcedure; cmd.Parameters.AddWithValue("@prodname", txtpname.Text ); cmd.Parameters.AddWithValue("@unitprice", txtup.Text); conn.Open(); int feedback = cmd.ExecuteNonQuery(); conn.Close(); MessageBox.Show(feedback + " record inserted"); txtpname.Clear(); txtup.Clear(); conn.Open(); cmd = new SqlCommand("select * from products where productid>77",conn); SqlDataReader reader = cmd.ExecuteReader(); DataTable table = new DataTable(); table.Load(reader); conn.Close(); dataGridView1.DataSource = table; Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module12\DatabaseApplication\DatabaseApplication\08spin.cs)

201

CommandBuilder for Update Data in Disconnected Architecture

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(Source code: Module12\DatabaseApplication\DatabaseApplication\05CommandBuilder.cs) CommandBuilder - Automatically generates single-table commands that are used to

reconcile changes made to a DataSet with the associated database. Minimum requirement to pass the select command (select query) with command builder object. When associated with a DataAdapter, the DbCommandBuilder automatically generates the InsertCommand, UpdateCommand, and DeleteCommand properties of the DataAdapter The SelectCommand must also return at least one primary key or unique column. If none are present, an InvalidOperation exception is generated, and the commands are not generated.

202

Code for update data using CommandBuilder • Declare Class level members SqlConnection conn; SqlDataAdapter adp; SqlCommandBuilder cb; DataTable table;

• Write the following code in load event conn = new SqlConnection(connstr); string sql = "select * from products"; adp = new SqlDataAdapter(sql, conn); cb = new SqlCommandBuilder(adp); table = new DataTable(); adp.Fill(table); DataColumn[] pk = new DataColumn [1]; pk[0] = table.Columns["productid"]; table.PrimaryKey = pk; dataGridView1.DataSource = table; Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module12\DatabaseApplication\DatabaseApplication\05CommandBuilder.cs)

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Code for update data using CommandBuilder • Write the following code for the Update button click event try { table = (DataTable )dataGridView1.DataSource; adp.Update(table ); MessageBox.Show("Data modified in the Database"); } catch (Exception ex) { MessageBox.Show(ex.Message); }

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(Source code: Module12\DatabaseApplication\DatabaseApplication\05CommandBuilder.cs)

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Data Navigation

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(Source code: Module12\DatabaseApplication\DatabaseApplication\06DataNavigation.cs)

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Data Navigation

(Contd…)

• Declare class level member SqlConnection conn; SqlDataAdapter adp; SqlCommandBuilder cb; DataSet ds; BindingManagerBase bm; int pid, flag; void Display() { txtpid.Text = ds.Tables["products"].Rows[bm.Position]["productid"].ToString(); txtpname.Text = ds.Tables["products"].Rows[bm.Position]["productname"].ToString(); txtup.Text = ds.Tables["products"].Rows[bm.Position]["unitprice"].ToString(); lblrecno.Text = bm.Position + 1 + " / " + bm.Count; } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module12\DatabaseApplication\DatabaseApplication\06DataNavigation.cs)

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Data Navigation

(Contd…)

• Code for load event string connstr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString; conn = new SqlConnection(connstr); string sql = "select productid, productname,unitprice from products"; adp = new SqlDataAdapter(sql, conn); cb = new SqlCommandBuilder(adp); ds = new DataSet(); adp.Fill(ds, "products"); DataColumn[] pk = new DataColumn[1]; pk[0] = ds.Tables["products"].Columns["productid"]; ds.Tables["products"].PrimaryKey = pk; bm = this.BindingContext[ds, "products"]; bm.Position = 0; Display();

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(Source code: Module12\DatabaseApplication\DatabaseApplication\06DataNavigation.cs)

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Data Navigation

(Contd…)

• First Button bm.Position = 0 Display()

• Next Button bm.Position += 1 Display()

• Prior Button bm.Position -= 1 Display()

• Last Button bm.Position = bm.Count - 1 Display()

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(Source code: Module12\DatabaseApplication\DatabaseApplication\06DataNavigation.cs)

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Data Navigation

(Contd…)

• Add Button txtpid.Clear(); txtpname.Clear(); txtup.Clear(); flag = 1; btnsave.Enabled = true;

• Edit Button pid =int.Parse ( txtpid.Text); flag = 2; btnsave.Enabled = true;

• Delete Button DialogResult result = MessageBox.Show("Are you sure, you want to delete the record?", "Delete Box", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2); if (result == DialogResult.Yes) { MessageBox.Show("Click save button to delete the record"); pid = int.Parse(txtpid.Text); flag = 3; btnsave.Enabled = true; }

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(Source code: Module12\DatabaseApplication\DatabaseApplication\06DataNavigation.cs)

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Data Navigation

(Contd…)

• Save Button DataRow dr; if (flag == 1) { //Add dr = ds.Tables["products"].NewRow(); dr["productid"] = 0; dr["productname"] = txtpname.Text; dr["unitprice"] = decimal.Parse(txtup.Text); ds.Tables["products"].Rows.Add(dr); } else if (flag == 2) { //Edit dr = ds.Tables["products"].Rows.Find(pid); if (dr != null) { dr.BeginEdit(); dr["productid"] = pid; dr["productname"] = txtpname.Text; dr["unitprice"] = decimal.Parse(txtup.Text); dr.EndEdit(); } }

else if (flag == 3) { //Delete dr = ds.Tables["products"].Rows.Find(pid); if (dr != null) { dr.Delete(); } }

adp.Update(ds, "products"); MessageBox.Show("Data modified"); ds.Clear(); adp.Fill(ds, "products"); bm.Position = 0; Display(); flag = 0; btnsave.Enabled = false;

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(Source code: Module12\DatabaseApplication\DatabaseApplication\06DataNavigation.cs)

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Data Navigation

(Contd…)

• Concurrency Check catch (Exception ex) { MessageBox.Show(ex.Message); if (ds.HasErrors) { foreach(DataTable table in ds.Tables) { if (table.HasErrors) { foreach (DataRow row in table.Rows) { if (row.HasErrors) { MessageBox.Show("Table : " + table.TableName + "\n Row : " + row["productid"].ToString() + "\n" + row.RowError, "Error Box"); row.ClearErrors(); row.RejectChanges(); } } } } } Pragati Software Pvt. Ltd., 312, }Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com 211

(Source code: Module12\DatabaseApplication\DatabaseApplication\06DataNavigation.cs)

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Data Navigation

(Contd…)

• Exit Button Application.Exit();

• Find Button _06FindProduct frm = new _06FindProduct(); frm.ShowDialog(); int productid = frm.prodid; //MessageBox.Show(productid.ToString()); if (productid > 0) { DataRow dr = ds.Tables["products"].Rows.Find(productid); if (dr != null) MessageBox.Show("Product ID : " + dr["productid"] + "\nProduct Name : " + dr["productname"] + "\nUnit Price : " + dr["unitprice"], "Display Box"); else MessageBox.Show("Record not found", "Display Box");

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(Source code: Module12\DatabaseApplication\DatabaseApplication\06DataNavigation.cs)

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Data Navigation

(Contd…)

public _06FindProduct() { InitializeComponent(); } public int prodid; private void btnsubmit_Click(object sender, EventArgs e) { if (txtprodid.Text == "") prodid = 0; else prodid = int.Parse (txtprodid.Text); this.Close(); } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module12\DatabaseApplication\DatabaseApplication\06FindProduct.cs)

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Master Detail Relationship

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(Source code: Module12\DatabaseApplication\DatabaseApplication\07MasterDetail.cs)

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Master Detail Relationship

(Contd…)

Class level declaration SqlConnection conn; SqlDataAdapter adp; SqlCommandBuilder cb; DataSet ds; BindingManagerBase bm; void Display() { txtcatid.Text = ds.Tables["categories"].Rows[bm.Position]["categoryid"].ToString(); txtcatname.Text = ds.Tables["categories"].Rows[bm.Position]["categoryname"].ToString(); lblrecno.Text = bm.Position + 1 + " / " + bm.Count; int catid = int.Parse(txtcatid.Text); DataView view = ds.Tables["products"].DefaultView; view.RowFilter = "categoryid=" + catid; dataGridView1.DataSource = view; } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module12\DatabaseApplication\DatabaseApplication\07MasterDetail.cs)

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Master Detail Relationship

(Contd…)

Form Load Event string connstr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString; conn = new SqlConnection(connstr); string sqlcategory = "select categoryid, categoryname from categories order by categoryid"; string sqlproduct = "select productid, productname,unitprice, categoryid from products"; adp = new SqlDataAdapter(sqlcategory, conn); ds = new DataSet(); adp.Fill(ds, "categories"); SqlCommand selectcmd = new SqlCommand(sqlproduct, conn); adp.SelectCommand = selectcmd ; adp.Fill(ds, "products"); bm = this.BindingContext[ds, "categories"]; bm.Position = 0; Display(); Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module12\DatabaseApplication\DatabaseApplication\07MasterDetail.cs)

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Master Detail Relationship

(Contd…)

• First Button bm.Position = 0; Display();

• Previous Button bm.Position = bm.Position + 1; Display();

• Next Button bm.Position = bm.Position + 1; Display();

• Last Button bm.Position = bm.Count - 1; Display();

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(Source code: Module12\DatabaseApplication\DatabaseApplication\07MasterDetail.cs)

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Stored Procedure with Out Parameter

• Write the following stored procedure in the MS SQL Server create proc TotalProduct (@catid int, @count int output) as select @count=count(productid) from products where Categoryid = @catid

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(Source code: Module12\DatabaseApplication\DatabaseApplication\09spout.cs)

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Stored Procedure with Out Parameter

(Contd…)

• Form Load event populate the list box string connstr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString; SqlConnection conn = new SqlConnection(connstr); string sql = "select categoryid, categoryname from categories order by categoryid"; SqlDataAdapter adp = new SqlDataAdapter(sql,conn); DataSet ds = new DataSet(); adp.Fill(ds,"categories"); lstcategory.DisplayMember = ds.Tables["categories"].Columns["categoryname"].ToString(); lstcategory.ValueMember = ds.Tables["categories"].Columns["categoryid"].ToString(); lstcategory.DataSource = ds.Tables["categories"];

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(Source code: Module12\DatabaseApplication\DatabaseApplication\09spout.cs)

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Stored Procedure with Out Parameter

(Contd…)

• Type the following code in the ListBox SelectedIndexChanged event string connstr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString; SqlConnection conn = new SqlConnection(connstr); SqlCommand cmd = new SqlCommand("TotalProduct", conn); cmd.CommandType = CommandType.StoredProcedure; cmd.Parameters.AddWithValue("@catid", int.Parse(lstcategory.SelectedValue.ToString() )); cmd.Parameters.Add("@count", SqlDbType.Int); cmd.Parameters[1].Direction = ParameterDirection.Output; conn.Open(); cmd.ExecuteNonQuery(); conn.Close(); lblresult.Text = "Total Product for catgory " + lstcategory.SelectedValue.ToString() + " = " + cmd.Parameters[1].Value.ToString(); Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module12\DatabaseApplication\DatabaseApplication\09spout.cs)

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Transaction

int result1, result2; string connstr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString; SqlConnection conn = new SqlConnection(connstr); conn.Open();

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(Source code: Module12\DatabaseApplication\DatabaseApplication\10Transaction.cs)

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Transaction

(Contd…)

cmd = conn.CreateCommand(); cmd.Connection = conn; cmd.CommandText = "insert into products (productname, unitprice) values ('Ipod',25000)"; MyTransaction = conn.BeginTransaction(); cmd.Transaction = MyTransaction; result1 = cmd.ExecuteNonQuery(); cmd.CommandText = "update products set unitprice=0 where productid=80"; result2 = cmd.ExecuteNonQuery(); if (result1 > 0 && result2 > 0) { MyTransaction.Commit(); MessageBox.Show("Transaction saved, Data modified"); } else { MyTransaction.Rollback(); MessageBox.Show("Transaction Rollback"); } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module12\DatabaseApplication\DatabaseApplication\10Transaction.cs)

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DataRelation

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(Source code: Module12\DatabaseApplication\DatabaseApplication\11DataRelation.cs)

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DataRelation

(Contd…)

• Form Load Event decimal total; string connstr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString; SqlConnection conn = new SqlConnection(connstr); SqlDataAdapter adpcategory = new SqlDataAdapter("select * from Categories", conn); SqlDataAdapter adpprod = new SqlDataAdapter("select * from products", conn); DataSet ds = new DataSet(); adpcategory.Fill(ds, "categories"); adpprod.Fill(ds, "products"); ds.Relations.Add("category", ds.Tables["categories"].Columns["categoryid"], ds.Tables["products"].Columns["categoryid"]);

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(Source code: Module12\DatabaseApplication\DatabaseApplication\11DataRelation.cs)

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DataRelation

(Contd…)

foreach (DataRow catrow in ds.Tables["categories"].Rows) { total = 0; lstrelation.Items.Add("CategoryID = " + catrow["categoryid"] + " " + "Category Name = " + catrow["categoryName"]); lstrelation.Items.Add("-------------------------------"); foreach (DataRow prodrow in catrow.GetChildRows("category")) { lstrelation.Items.Add("Productname = " + prodrow["productname"] + " " + "unitPrice = " + prodrow["unitprice"]); total += decimal.Parse(prodrow["unitprice"].ToString()); } lstrelation.Items.Add("-------------------------------------------------"); lstrelation.Items.Add("Total = " + total); lstrelation.Items.Add("-------------------------------------------------"); } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

225

(Source code: Module12\DatabaseApplication\DatabaseApplication\11DataRelation.cs)

225

Module 14. Data Bound Control • Overview ¾ Populating DataGridView Control using Wizard ¾ Populating ListBox Control using Wizard ¾ Binding Navigator

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226

Populating DataGridView Control using Wizard • Add DataGridView Control from the data menu • Click on the smart tag • Click on Choose Data Source Drop Down arrow

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(Source code: Module 13\DataBoundControl\DataBoundControl\01DataGridControl.cs)

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Populating DataGridView Control using Wizard

(Contd…)

• Click on Add Project Data Source

• Select Database and click Next option

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(Source code: Module 13\DataBoundControl\DataBoundControl\01DataGridControl.cs)

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Populating DataGridView Control using Wizard

(Contd…)

• Click New Connection Button and specify the name of the SQL Server, Authentication and Database. • Click on Test Connection button. • If you get the message Test Connection Succeeded then click on OK button.

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(Source code: Module 13\DataBoundControl\DataBoundControl\01DataGridControl.cs)

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Populating DataGridView Control using Wizard

(Contd…)

• Save the connection String in Application Configuration file • Click Next Button

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230

(Source code: Module 13\DataBoundControl\DataBoundControl\01DataGridControl.cs)

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Populating DataGridView Control using Wizard

(Contd…)

• Select “Categories” table from the list and click “Finish” button

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(Source code: Module 13\DataBoundControl\DataBoundControl\01DataGridControl.cs)

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Populating DataGridView Control using Wizard

(Contd…)

• Display the data in grid

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232

(Source code: Module 13\DataBoundControl\DataBoundControl\01DataGridControl.cs)

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Populating ListBox Control using Wizard • Add ListBox from the Common Controls • Click on smart option • Check “Use data bound items”

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233

(Source code: Module 13\DataBoundControl\DataBoundControl\02ListBoxControl.cs)

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Populating ListBox using Wizard (Contd…) • Select Data Source option • Specify Display Member and Value Member options

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(Source code: Module 13\DataBoundControl\DataBoundControl\02ListBoxControl.cs)

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Populating ListBox using Wizard (Contd…) • Add the Label and name the label as lblcatid. • Write the following code in the listbox SelectedIndexChanged event private void listBox1_SelectedIndexChanged(object sender, EventArgs e) { if (listBox1.SelectedValue != null) lblcatid.Text = listBox1.SelectedValue.ToString(); }

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235

(Source code: Module 13\DataBoundControl\DataBoundControl\02ListBoxControl.cs)

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Populating ListBox using Wizard (Contd…) • Run the Form • Display Member property is used for display the column in the ListBox. • When we select the option from the ListBox it will display the Value Member.

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(Source code: Module 13\DataBoundControl\DataBoundControl\02ListBoxControl.cs)

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Binding Navigator • • • • •

Add Binding Source Control from the Data Tab. Go to Property window and specify DataSource Property. Add 2 Labels and 2 Textboxes Add Binding Navigator Control from Data Tab. Go to Property window and specify BindingSource Property as BindingSource1 • DataMember Property as Categories • Select the txtcatid TextBox and assign the DataBinding Text property as Categoryid • Select the txtcatname TextBox and assign the DataBinding Text property as CategoryName

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(Source code: Module 13\DataBoundControl\DataBoundControl\03Navigator.cs)

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Binding Navigator

(Contd…)

• Run and Test the Program

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238

(Source code: Module 13\DataBoundControl\DataBoundControl\03Navigator.cs)

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Module 15. DotNet Framework & Assembly • Overview ¾ ¾ ¾ ¾ ¾ ¾ ¾ ¾

.Net Framework Assembly Type of Assembly Create Class Library Create Test Application Creating Shared Assembly Viewing the Manifest File Process of compiling and executing managed code

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239

Assembly

Assembly Manifest Module Metadata MSIL Types

Types

Types

Types

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An assembly is a single deployable unit that contains all the information about the implementation of classes, structure, interfaces, enum and delegates. An assembly stores all the information about itself. The information is called metadata, which includes the name and version number of the assembly, security information, information about the dependencies, and a list of the files that constitute the assembly. Assembly is a logical EXE or DLL. An assembly consists of manifest, module and type. Manifest – is the descriptor of the assembly. Module – is either a DLL or EXE. Type – can be a class, interface, structure, enum, delegates that contains data and logic.

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Types of Assembly • Private Assembly • Shared Assembly

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Private Assembly A private assembly is deployed and used exclusively with a single name. A private assembly is referenced by its simple name The simple name is defined in the assembly’s metadata. When you refer to private assembly , it get copied into the project which is referring to this assembly. Shared Assembly Shared assembly is also known as Strong Named Assembly It gives support to versioning and security of assembly Strong named assembly will have unique identification When you refer to shared assembly , it will not create the local copy of this assembly. It always refer to the location from where you have included the reference. Identity consist of •Simple Text Name •Version Number •Culture Information •Public Key •Digital Signature

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Creating Shared Assembly

(Contd…)

• Adding the dll file in GAC folder ¾ (C:\WINDOWS\Microsoft.NET\assembly\GAC_MSIL)

• Start MS Visual Studio Command Prompt and go to the folder where you have stored your dll file. ¾ (Start – Program – Microsoft Visual Studio 2010 – Visual Studio Tools – Visual Studio 2010 Command Prompt )

• Generate strong name key. ¾ Sn -k key.snk calc.snk

• • • •

Type the following command at the command prompt gacutil –i calculatorlib.dll This command will register the assembly in GAC Now when you add the reference of the assembly into your application, it will not create the local copy of assembly, it will maintain the reference to the folder from where you are adding the assembly.

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Viewing Manifest File

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Intermediate Language Disassembler (ILDASM) ILDASM is a tool for viewing the contents of assembly. Each assembly has a single manifest file which contains metadata. Go to Microsoft Visual Studio command Prompt and type ILDASM or go to start – program – Microsoft Windows SDK V6.OA – Tools – IL Disassembler Select File menu Click Open Select exe or dll file for which you want to see IL code

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Module 16. Delegate • Overview ¾ Understanding Delegate ¾ SingleCast Delegate ¾ MultiCast Delegate ¾ Anonymous Method

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Understanding Delegate • Declaring and invoking Delegate involves 4 steps ¾ Delegate declaration delegate returntype Name ([parameters]) ¾ Declare Delegate method Returntype Name ([parameters]) ¾ Delegate instantiation delegatename instancename = new delegatename(methodname) ¾ Delegate invocation Instancename(parameters value)

• Use of Delegate ¾ Events ¾ Threads ¾ Asynchronous Application Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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Features of Delegate •Delegate is one of the type which we can declare within the Namespace. •Delegates are termed as function pointers. •Delegates contain the address of the method that is to be executed. •Signature of delegate and method signature should be identical. •Delegates act as middle layer to communicate the event occurred to the system. •There are two types of delegates Singlecast and multicast. ¾Singlecase delegate can hold and invoke single method ¾Multicast delegate can hold and invoke multiple methods.

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SingleCast Delegate //Declare Delegate delegate void DelegateString(string s); delegate int DelegateCube(int number); class _01SingleCastDelegate { //method public static void Greet(string Name) { Console.WriteLine("Hello..." + Name); } //method public static void Wish(string Name) { int Hour = System.DateTime.Now.Hour; if (Hour >= 5 && Hour < 12) Console.WriteLine("Good Morning..." + Name); else if (Hour >= 12 && Hour < 16) Console.WriteLine("Good Afternoon..." + Name); else if (Hour >= 16 && Hour < 22) Console.WriteLine("Good Evening..." + Name); else Console.WriteLine("Good Night..." + Name); } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module 15\DelegateExample\DelegateExample\01SingleCastDelegate.cs)

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SingleCast Delegate

(Contd…)

//method public static int NumberCube(int number) { return number * number * number; } public static void Main() { //instantiate delegate DelegateString delegateobj1 = new DelegateString(Greet); DelegateString delegateobj2 = new DelegateString(Wish ); //Invoke delegate delegateobj1("Bhavana"); Console.WriteLine("-----------------------------------"); delegateobj2("Bhavana"); Console.WriteLine("====================================="); DelegateCube delegatecubeobj = new DelegateCube(NumberCube); Console.WriteLine("Cube of Number 3 = " + delegatecubeobj(3)); Console.ReadLine(); } } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module 15\DelegateExample\DelegateExample\01SingleCastDelegate.cs)

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MultiCast Delegate delegate void DelegateMultiCast (int value1, int value2); class _02MultiCastDelegate { public static void AddNumbers(int number1, int number2) { int total = number1 + number2; Console.WriteLine("Addition of 2 numbers {0}, {1} = {2}", number1, number2,total); } public static void MultiplyNumbers(int number1, int number2) { int total = number1 * number2; Console.WriteLine("Multiplication of 2 numbers {0}, {1} = {2}", number1, number2, total); }

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(Source code: Module 15\DelegateExample\DelegateExample\02MultiCastDelegate.cs) Using multicast delegate you can call more then one method through single delegate instance. It will successively call each method in order. The delegate signature should return a void, otherwise, you would only get the result of the last invoked method. If one of the method invoked by the delegate throws an exception, the execution stops.

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MultiCast Delegate

(Contd…)

public static void Power(int number1, int number2) { int total=1; for (int i = 1; i System.DateTime.Now.DayOfYear) { intAge -= 1; } } return intAge; } } } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Appendix Serialization\Serialization\Serialization\02BinarySerialization.cs\Person.cs)

Binary Serialization Binary Formatter class is available in the namespace System.Runtime.Serialization.Formatters.Binary

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(Source code: Appendix Serialization\Serialization\Serialization\02BinarySerialization.cs)

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Binary Serialization Write Object • Add the namespace using System.Runtime.Serialization.Formatters.Binary; using System.IO; Person p = new Person("Bhavana", Convert.ToDateTime("01/01/2001")); FileStream stream = new FileStream("c:\\Person.txt", FileMode.Create ); BinaryFormatter formatter = new BinaryFormatter(); formatter.Serialize(stream, p); stream.Close(); richTextBox1.Text = "Data saved in a file";

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(Source code: Appendix Serialization\Serialization\Serialization\02BinarySerialization.cs)

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Binary Serialization Read Object richTextBox1.Clear(); FileStream stream = new FileStream("c:\\Person.txt", FileMode.Open); BinaryFormatter formatter = new BinaryFormatter(); Person p =(Person) formatter.Deserialize(stream); stream.Close(); richTextBox1.AppendText("Name = " + p.Name + "\nAge = " + p.Age); richTextBox1.AppendText("\nBirthdate = " + p.Birthdate);

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(Source code: Appendix Serialization\Serialization\Serialization\02BinarySerialization.cs)

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Read & Write Multiple Object List personlist = new List(); personlist.Add(new Person("Bhavana", Convert.ToDateTime("01/01/2001"))); personlist.Add(new Person("Shraddha", Convert.ToDateTime("01/01/2002"))); personlist.Add(new Person("Vishal", Convert.ToDateTime("01/01/2003"))); FileStream stream = new FileStream("C:\\Persons.txt", FileMode.Create); BinaryFormatter formatter = new BinaryFormatter(); formatter.Serialize(stream, personlist); stream.Close(); FileStream stream1 = new FileStream("C:\\Persons.txt", FileMode.Open); List TotalPersons = (List)formatter.Deserialize(stream1); stream1.Close(); foreach (Person p in TotalPersons) { richTextBox1.AppendText(p.Name + " " + p.Birthdate + " " + p.Age.ToString() + "\n"); } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

(Source code: Appendix Serialization\Serialization\Serialization\02BinarySerialization.cs)

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SOAP Serialization Add reference for the namespace System.Runtime.Serialization.Formatters.Soap

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(Source code: Appendix Serialization\Serialization\Serialization\03SOAPSerialization.cs)

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SOAP Serialization Write Object Person p = new Person("Bhavana", Convert.ToDateTime("01/01/2001")); FileStream stream = new FileStream("c:\\PersonSoap.XML", FileMode.Create); SoapFormatter formatter = new SoapFormatter(); formatter.Serialize(stream, p); stream.Close(); richTextBox1.Text = "Data saved in a file";

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(Source code: Appendix Serialization\Serialization\Serialization\03SOAPSerialization.cs)

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SOAP Serialization Read Object richTextBox1.Clear(); FileStream stream = new FileStream("c:\\PersonSoap.XML", FileMode.Open); SoapFormatter formatter = new SoapFormatter(); Person p = (Person)formatter.Deserialize(stream); stream.Close(); richTextBox1.AppendText("Name = " + p.Name + "\nAge = " + p.Age); richTextBox1.AppendText("\nBirthdate = " + p.Birthdate); richTextBox1.AppendText("\nBirthdate day of the year = " + p.Birthdate.DayOfYear.ToString()); richTextBox1.AppendText("\nCurrent day of the year = " + DateTime.Now.DayOfYear.ToString());

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(Source code: Appendix Serialization\Serialization\Serialization\03SOAPSerialization.cs)

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XML Serialization • Rules for creating class for XML Serialization ¾ XML serialization serializes only the public fields and property values of an object into an XML stream. ¾ XML serialization does not include type information. ¾ XML serialization serialize only the public type. ¾ XML serialization requires a default constructor to be declared in the class that is to be serialized. ¾ XML serialization requires all properties that are to be serialized as read write properties. Read only properties are not serialized.

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XML was designed to be a technology for data exchange across heterogeneous systems. It can be easily transmitted between distributed components because of its platform independence and its simple, text-based, self-describing format.

Employee Class • Add the following namespace using System.Xml.Serialization; using System.Collections;

public class Emp { [XmlAttribute("empNo")] public int empNo; [XmlElement("name")] public string name; //[XmlElement("address")] [XmlIgnore] public string address; [XmlElement("salary")] public double salary; Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Appendix Serialization\Serialization\Serialization\Employee.cs)

Employee Class (Contd…) public Emp() {} public Emp(int empNo,string name, string address, double sal) { this.empNo = empNo; this.name = name; this.address = address; this.salary = sal; } public double AnnualSalary() { return salary * 12; } }

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(Source code: Appendix Serialization\Serialization\Serialization\Employee.cs)

Employee Class (Contd…) [XmlRoot("employeeList")] public class Employee { private ArrayList listEmployee; public Employee() { listEmployee = new ArrayList(); } public int AddEmp(Emp emp) { return listEmployee.Add(emp); }

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(Source code: Appendix Serialization\Serialization\Serialization\Employee.cs)

Employee Class (Contd…) [XmlElement("emp")] public Emp[] Emps { get { Emp[] emps = new Emp[listEmployee.Count]; listEmployee.CopyTo(emps); return emps; } Set { if (value == null) return; Emp[] emps = (Emp[])value; listEmployee.Clear(); foreach (Emp emp in emps) listEmployee.Add(emp); } } }

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(Source code: Appendix Serialization\Serialization\Serialization\Employee.cs)

Employee XML Serialization using System.IO; using System.Xml.Serialization;

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(Source code: Appendix Serialization\Serialization\Serialization\Employee.cs)

XML Serialization Write Object Employee empList = new Employee(); empList.AddEmp(new Emp(1,"Bhavana", "Mumbai", 8000.00)); empList.AddEmp(new Emp(2,"Shraddha", "Pune", 7000.00)); empList.AddEmp(new Emp(3,"Vishal", "Delhi", 9000.00)); //serialization XmlSerializer serializer = new XmlSerializer(typeof(Employee)); StreamWriter writer = new StreamWriter("C:\\emp.xml"); serializer.Serialize(writer, empList); writer.Close();

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(Source code: Appendix Serialization\Serialization\Serialization\04EmployeeXMLSerialization.cs)

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XML Serialization Read Object richTextBox1.Clear(); Employee newList; XmlSerializer serializer = new XmlSerializer(typeof(Employee)); StreamReader reader = new StreamReader("C:\\emp.xml"); newList = (Employee) serializer.Deserialize(reader); reader.Close(); int empcount = newList.Emps.Count(); richTextBox1.AppendText("total No of Employees = " + empcount.ToString() + "\n"); for (int i = 0; i < empcount; i++) { richTextBox1.AppendText(newList.Emps[i].empNo.ToString() +" " + newList.Emps[i].name + " " + newList.Emps[i].address + " " + newList.Emps[i].salary.ToString() +" " + newList.Emps[i].AnnualSalary().ToString() + "\n"); }

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(Source code: Appendix Serialization\Serialization\Serialization\04EmployeeXMLSerialization.cs)

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Appendix:SQL Bulk Copy

string connstr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString; SqlConnection conn = new SqlConnection(connstr); conn.Open(); SqlCommand cmdcreatetable = new SqlCommand("create table Productnew1 (prodid int, prodname varchar(40))", conn); cmdcreatetable.ExecuteNonQuery(); conn.Close();

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(Source code: Module12\DatabaseApplication\DatabaseApplication\12SQLBulkCopy.cs)

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SQL Bulk Copy

(Contd…)

SqlConnection Sourceconn = new SqlConnection(connstr); Sourceconn.Open(); SqlCommand cmd = new SqlCommand("select productid, productname from products where productid > 70 and Productid 70", conn); adp.UpdateCommand.UpdatedRowSource = UpdateRowSource.None; adp.UpdateBatchSize = 2; adp.Update(ds); label1.Text = "Row updated = " + x; label2.Text = "Rwo updating = " + y; private void adprowupdated(object sender, EventArgs e) { x++; } private void adprowupdating(object sender, EventArgs e) { y++; } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module12\DatabaseApplication\DatabaseApplication\13BatchUpdate.cs)

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Appendix : Multiple Active Result Set

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(Source code: Module12\DatabaseApplication\DatabaseApplication\14MARS.cs)

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Multiple Active Result Set

(Contd…)

//By default, MARS is disabled when connecting to a MARS-enabled host such as SQL Server 2005. It must be enabled in the connection string. int categoryid; SqlDataReader productReader = null; string categorysql = "select categoryid, categoryname from categories"; string productsql = "select productid, productname from products where categoryid=@catid"; using (SqlConnection Connection = new SqlConnection("Data Source = .\\sa1; Integrated Security=true;Initial Catalog= Northwind; MultipleActiveResultSets=True“ )) { SqlCommand categoryCmd = new SqlCommand(categorysql, Connection); SqlCommand productCmd = new SqlCommand(productsql, Connection); productCmd.Parameters.Add("@catid", SqlDbType.Int); Connection.Open();

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(Source code: Module12\DatabaseApplication\DatabaseApplication\14MARS.cs)

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Multiple Active Result Set

(Contd…)

using (SqlDataReader categoryReader = categoryCmd.ExecuteReader()) { while (categoryReader.Read()) { lstmars.Items.Add (categoryReader["categoryname"].ToString()); categoryid = (int)categoryReader["categoryid"]; productCmd.Parameters["@catid"].Value = categoryid; // The following line of code requires a MARS-enabled connection. productReader = productCmd.ExecuteReader(); using (productReader) { while (productReader.Read()) { lstmars.Items.Add (" " + productReader[“productName”].ToString()); } } } Connection.Close(); } } }

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(Source code: Module12\DatabaseApplication\DatabaseApplication\14MARS.cs)

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Appendix : Reading and Writing Data to XML

DataSet ds;

• Form Load Event string connstr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString; SqlConnection conn = new SqlConnection(connstr); string sql = "select categoryid, categoryname from categories order by categoryid"; SqlDataAdapter adp = new SqlDataAdapter(sql, conn); ds = new DataSet(); adp.Fill(ds); Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module12\DatabaseApplication\DatabaseApplication\15XML.cs)

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Reading and Writing Data to XML

(Contd…)

• WriteXML Button if (!File.Exists("C:\\category.xml")) { ds.WriteXml("c:\\category.xml"); } btnreadxml.Visible = true;

• ReadXML Button ds.Clear(); ds.ReadXml("C:\\category.xml"); dataGridView1.DataSource = ds.Tables[0];

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(Source code: Module12\DatabaseApplication\DatabaseApplication\15XML.cs)

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Appendix : Data Independent Provider

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(Source code: Module12\DatabaseApplication\DatabaseApplication\16ProviderFactories.cs)

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Data Independent Provider

(Contd…)

• Add the following namespace •

using System.Data.Common;

• Form Load Event DataTable table = DbProviderFactories.GetFactoryClasses(); lstprovider.DisplayMember = table.Columns["InvariantName"].ToString(); lstprovider.ValueMember = table.Columns["InvariantName"].ToString(); lstprovider.DataSource = table;

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(Source code: Module12\DatabaseApplication\DatabaseApplication\16ProviderFactories.cs)

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Data Independent Provider

(Contd…)

• ListBox SelectedIndexChange Event string provider = lstprovider.SelectedValue.ToString(); if (provider == "System.Data.SqlClient") { DbProviderFactory factory = DbProviderFactories.GetFactory(provider ); using (DbConnection conn = factory.CreateConnection()) { conn.ConnectionString = "data source=.\\sa1; initial catalog=northwind; integrated security=true"; conn.Open(); DbCommand cmd = factory.CreateCommand(); cmd.CommandText = "select * from customers"; cmd.Connection = conn; DbDataReader reader = cmd.ExecuteReader(); DataTable custtable = new DataTable(); custtable.Load(reader); conn.Close(); dataGridView1.DataSource = custtable; } } Pragati Software Pvt. Ltd., 312, Lok Center, Marol-Maroshi Road, Marol, Andheri (East), Mumbai 400 059. www.pragatisoftware.com

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(Source code: Module12\DatabaseApplication\DatabaseApplication\16ProviderFactories.cs)

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Data Independent Provider

(Contd…)

else if (provider == "System.Data.OleDb") { DbProviderFactory factory = DbProviderFactories.GetFactory(provider ); using (DbConnection conn = factory.CreateConnection()) { conn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;data source=c:\\northwind.mdb;"; conn.Open(); DbCommand cmd = factory.CreateCommand(); cmd.CommandText = "select * from Categories"; cmd.Connection = conn; DbDataReader reader = cmd.ExecuteReader(); DataTable categorytable = new DataTable(); categorytable.Load(reader); conn.Close(); dataGridView1.DataSource = categorytable; } }

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(Source code: Module12\DatabaseApplication\DatabaseApplication\16ProviderFactories.cs)

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Appendix : TreeView Example with Database

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(Source code: Module12\DatabaseApplication\DatabaseApplication\17TreeViewExample.cs)

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TreeView Example with Database Code • Class level declaration SqlConnection conn; SqlDataAdapter adp; DataSet ds = new DataSet();

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TreeView Example with Database Code • Form Load Event conn = new SqlConnection("server=.\\sa1;database=northwind;integrated security=true"); adp = new SqlDataAdapter("select table_name from information_schema.tables where table_type='Base Table' order by table_name", conn); adp.Fill(ds); treeView1.Nodes.Add("Northwind"); int rows = ds.Tables[0].Rows.Count; for (int i = 0; i