S4 Files and Storage

M4: Files and Storage in Windows Phone 8

Target Agenda | Day 1 Module and Topic | 10-minute breaks after each session / 6060 -minute “meal break”

Planned Duration

1a - Introducing Windows Phone 8 Application Development | Part 1

50:00

1b - Introducing Windows Phone 8 Application Development | Part 2

50:00

2 - Designing Windows Phone Apps

50:00

3 - Building Windows Phone Apps

50:00

4 - Files and Storage on Windows Phone 8

50:00

Meal Break | 60-minutes

60:00

5 - Windows Phone 8 Application Lifecycle

50:00

6 - Background Agents

25:00

7 - Tiles and Lock Screen Notifications

25:00

8 - Push Notifications

30:00

9 - Using Phone Resources on Windows Phone 8

50:00

Target Agenda | Day 1 Module and Topic | 10-minute breaks after each session / 6060 -minute “meal break”

Planned Duration

1a - Introducing Windows Phone 8 Application Development | Part 1

50:00

1b - Introducing Windows Phone 8 Application Development | Part 2

50:00

2 - Designing Windows Phone Apps

50:00

3 - Building Windows Phone Apps

50:00

4 - Files and Storage on Windows Phone 8

50:00

Meal Break | 60-minutes

60:00

5 - Windows Phone 8 Application Lifecycle

50:00

6 - Background Agents

25:00

7 - Tiles and Lock Screen Notifications

25:00

8 - Push Notifications

30:00

9 - Using Phone Resources on Windows Phone 8

50:00

Target Agenda | Day 2 Module and Topic | 10-minute breaks after each session / 6060 -minute “meal break”

Planned Duration

10 - App to App Communication

35:00

11 - Network Communication on Windows Phone 8

50:00

12 - Proximity Sensors and Bluetooth

35:00

13 - Speech Input on Windows Phone 8

35:00

14 - Maps and Location on Windows Phone 8

35:00

15 - Wallet Support

25:00

16 - In App Purchasing

25:00

Meal Break | 60-minutes

60:00

17 - The Windows Phone Stor Store e

50:00

18 - Enterprise Applications in Windows Phone 8: Architectur Architecture e and Publishing

50:00

19 - Windows 8 and Windows Phone 8 Cross Platform Developmen Developmentt

50:00

Module Agenda

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WP7.1IsolatedStorage and IsolatedStorageSettings APIs

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“Local Storage” and “Isolated Storage”

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Windows.Storage (Windows Phone Runtime) programming

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Special Folders Shared/Media Shared/ShellContent Shared/Transfers •

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Exploring the local folder with ISET Using Removable SD cards

Not Covered in this Module… •

Local Database •

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No change from WP 7.1 See these Jump Start modules: http://channel9.msdn.com/Series/Mango-Jump-Start/Mango-Jump-Start-08aApplication-Data-Storage-on-Windows-Phone--Part-1 http://channel9.msdn.com/Series/Mango-Jump-Start/Mango-Jump-Start-08bApplication-Data-Storage-on-Windows-Phone-Part-2 SQLite database (native only) •

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Persistent Storage in Windows Phone 8

Local Data Storage: Overview •

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Installation Folder

Package Manager installs all app files into the Installation Folder Read-only access from app Read-only reference database

WP7.1: “App Data”

Install

Package Manager DB

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Apps store data in Local Folder Settings and properties in the app dictionary Unstructured data in Isolated Storage files Structured data in database files

Database File (r/o)

App WP8 Storage APIs or WP7 Isolated Storage APIs Application Settings File

DB Database file

Application Files

Different Methods For Addressing Storage Locations File Type/ API

Installation Folder

Local Folder

Example

Local Database data context

appdata:/

isostore:/

MyDataContext db = new MyDataContext ("isostore:/mydb.sdf")

Files access using WP7.1 Isolated Storage API

not supported

StorageFile and StorageFolder APIs

var isf = IsolatedStorageFile.GetUserStoreForApplication()

File access using Windows.Storage API via URIs

ms-appx:///

msappdata:///local/

var file = await Windows.StorageFile.GetFileFromApplicationUriAsync ( new Uri("ms-appdata:///local/AppConfigSettings.xml" ));

File access using Windows.Storage API via StorageFolder references

Windows. ApplicationModel. Package.Current. InstalledLocation

Windows.Storage. ApplicationData. Current. LocalFolder

var localFolder = Windows.Storage.ApplicationData.Current.LocalFolder; Windows.Storage.StorageFile storageFile = await  localFolder.GetFileAsync("CaptainsLog.store");

WP8 File Access Alternatives •

Three ways of getting a reference to the same file:

// WP7.1 IsolatedStorage APIs var isf = IsolatedStorageFile .GetUserStoreForApplication(); IsolatedStorageFileStream  fs = new IsolatedStorageFileStream ("CaptainsLog.store" , FileMode.Open, isf)); ...

// WP8 Storage APIs using URI StorageFile storageFile = await Windows.Storage. StorageFile .GetFileFromApplicationUriAsync( new Uri("ms-appdata:///local/CaptainsLog.store " )); ...

// WP8 Storage APIs Windows.Storage. StorageFolder  localFolder = Windows.Storage. ApplicationData .Current.LocalFolder; Windows.Storage. StorageFile  storageFile = await  localFolder.GetFileAsync( "CaptainsLog.store" ); ...

Storing Data using WP7.1 Isolated Storage APIs

Isolated Storage Classes •

The IsolatedStorage classes are all in the System.IO.IsolatedStorage namespace •

IsolatedStorageFile •

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IsolatedFileStream •

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Represents an isolated storage area containing files and directories

Exposes a file stream access to a file stored within isolated storage

IsolatedStorageSettings •

Dictionary) that stores key-value pairs

in isolated storage

Saving Data private void saveGameToIsolatedStorage(string message) { using (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication()) { using (IsolatedStorageFileStream rawStream = isf.CreateFile("MyFile.store")) { StreamWriter writer = new StreamWriter(rawStream); writer.WriteLine(message); // save the message writer.Close(); } } }

Loading Data private string loadString() { string result = null; using (IsolatedStorageFile isf = IsolatedStorageFile .GetUserStoreForApplication()) { if (isf.FileExists("Myfile.store") { using (IsolatedStorageFileStream rawStream = isf.OpenFile(filename, System.IO.FileMode.Open)) { StreamReader reader = new StreamReader (rawStream); result = reader.ReadLine(); reader.Close(); } } } return result; }

Demo 1: Using Isolated Storage

Application Settings •

If you just want to store setting information •

Username = “Fred”

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TextColor = “Green”

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You can use the ApplicationSettings object in Isolated Storage

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You use this as you would a dictionary

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You then write the object to persistent storage

Saving Data in Settings void saveString(string message, string name) { IsolatedStorageSettings.ApplicationSettings[name] = message; IsolatedStorageSettings.ApplicationSettings.Save(); }

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The storage works as a dictionary

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But you have to remember to call Save when you have finished adding keys

Loading from Settings string loadString(string name) { if (IsolatedStorageSettings.ApplicationSettings.Contains(name)) { return (string)IsolatedStorageSettings.ApplicationSettings[name]; } else { return null; } } •

Test for the key before you try to find it or you will get an exception thrown

Demo 2: Using Settings Storage

Using Windows Phone Runtime Storage

Windows.Storage Classes Windows Phone Runtime storage classes are in the Windows.Storage namespace

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StorageFolder Represents a storage area containing files and directories StorageFile Represents a file and provides methods for manipulating them •

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Not supported on Windows Phone 8:

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ApplicationData.LocalSettings Use custom file or IsolatedStorageSettings •

Saving Data – Using StorageFolder using System.IO; using Windows.Storage; …

private async void saveToLocalFolderAsync(string message) { // Get a reference to the Local Folder StorageFolder localFolder = ApplicationData.Current.LocalFolder; // Create the file in the local folder, or if it already exists, just open it StorageFile storageFile = await localFolder.CreateFileAsync("Myfile.store", CreationCollisionOption.OpenIfExists); Stream writeStream = await storageFile.OpenStreamForWriteAsync(); using (StreamWriter writer = new StreamWriter(writeStream)) { await writer.WriteAsync(logData); } }

Loading Data using System.IO; using Windows.Storage; …

private async string loadStringAsync() { string theData = string.Empty; // Get a reference to the file in the Local Folder StorageFolder localFolder = ApplicationData.Current.LocalFolder; StorageFile storageFile = await localFolder.GetFileAsync(“Myfile.store")); // Open it and read the contents Stream readStream = await storageFile.OpenStreamForReadAsync(); using (StreamReader reader = new StreamReader(readStream)) { theData = await reader.ReadToEndAsync(); } return theData; }

Accessing Files Using ms-appdata:///local/ or ms-appx:/// // There's no FileExists method in WinRT, so have to try to open it and catch exception instead StorageFile storageFile = null; bool fileExists = false; try { // Try to open file using URI storageFile = await StorageFile.GetFileFromApplicationUriAsync( new Uri("ms-appdata:///local/Myfile.store")); fileExists = true; } catch (FileNotFoundException) { fileExists = false; } if (!fileExists) { await ApplicationData.Current.LocalFolder.CreateFileAsync("Myfile.store", CreationCollisionOption.FailIfExists); }

Windows Phone 8 – Windows 8 Compatibility Only LocalFolder Supported

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Windows Phone 8 implementation of Windows.Storage is a subset of Windows 8 WinRT All data storage uses the LocalFolder (equivalent to WP7.1 IsolatedStorage) •

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Not Supported: •

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Roaming Data Store: ApplicationData.Current.RoamingFolder Temporary Data Store: ApplicationData.Current.TemporaryFolder Local Settings: ApplicationData.Current.LocalSettings Roaming Settings: ApplicationData.Current.RoamingSettings

Windows Phone 8 – Windows 8 Compatibility Programmatically Accessing Image Files

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In Windows 8, you can programmatically load an Image file that you have included in your app package into a XAML element using the URI syntax, as follows: RecipeImage.Source = new System.Windows.Media.Imaging.BitmapImage( new Uri(@"ms-appx:///Images/french/French_1_600_C.jpg" , UriKind.RelativeOrAbsolute));

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In Windows Phone 8, you cannot use the URI syntax in this way. Continue to use the relative path to the image, as in Windows Phone OS 7.1: RecipeImage.Source = new System.Windows.Media.Imaging.BitmapImage("/Images/french/French_1_600_C.jpg");

Demo 3: Using Windows.Storage

Special Folders

Local Folder •

All read-write I/O operations restricted to local folder •

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Create a files and folder structure hierarchy Use Isolated Settings storage to store application settings

Reserved Folders •

In addition to general data storage, the local folder is used for the following special-use scenarios: •

Shared/Media - Apps can use this folder to display album art in the Universal Volume Control (UVC) while playing background audio

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Shared/ShellContent - Background images for Tiles can be stored in isolated storage, but must be located in this folder or a subfolder of it Shared/Transfers – Storage area used by the Background File Transfer service

Data Serialization and Deserialization

Data Serialization •

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Data persistence and the app lifecycle App Launch Deserialize data from Isolated Storage •

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Not running

App being dormant/tombstoned Serialize persistent data to Isolated Storage •

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App being reactivated Deserialize data from Isolated Storage •

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Deactivated  /Closing

Launching

App being terminated Serialize persistent data to Isolated Storage •

Running

Why Serialize? •

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Serializers write the properties of a collection of objects into a file so they can be stored in persistent storage Deserializers reverse this: read data out of a file and use it to ‘re-hydrate’ a collection of in-memory objects Many different serializers are available: XmlSerializer DataContractSerializer DataContractJsonSerializer Third party… •

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Serialization using DataContractSerializer public class MyDataSerializer { public static async Task SaveObjectsAsync(TheDataType sourceData, String targetFileName ) { StorageFile file = await ApplicationData .Current.LocalFolder.CreateFileAsync( targetFileName, CreationCollisionOption .ReplaceExisting); var outStream = await file.OpenStreamForWriteAsync(); DataContractSerializer  serializer = new DataContractSerializer (typeof(TheDataType)); serializer.WriteObject(outStream, sourceData); await outStream.FlushAsync(); outStream.Close(); } ... }

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To use: List myObjects = ... await MyDataSerializer.SaveObjectsAsync(myObjects, "MySerializedObjects.xml");

Deserialization using DataContractSerializer public class MyDataSerializer { public static async Task RestoreObjectsAsync( string fileName) { StorageFile file = await ApplicationData .Current.LocalFolder.GetFileAsync(fileName ); var inStream = await file.OpenStreamForReadAsync(); // Deserialize the objects. DataContractSerializer  serializer = new DataContractSerializer (typeof(TheDataType)); TheDataType data = (TheDataType)serializer.ReadObject(inStream ); inStream.Close (); return data; } ... } •

To use: List myObjects = await MyDataSerializer.RestoreObjectsAsync("MySerializedObjects.xml");

Demo 4: Serialization to Local Folder

Tools: Isolated Storage Explorer

Isolated Storage Explorer •

Isolated Storage Explorer is a command-line tool you use to list, copy, and replace files and directories in Isolated Storage • • •

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Can be used on emulator or device Can be used for applications that target Windows Phone OS 7.0, 7.1 and 8.0 Located at Program Files (x86)\Microsoft SDKs\Windows Phone\v8.0\Tools\IsolatedStorageExplorerTool

Syntax: ISETool.exe [] •

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ts – Take snapshot rs – Restore snapshot dir – Lists the files or directories

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xd – target the emulator de – target device from the WPAppManifest.xml file for the app

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Desktop-path – directory on your computer where isolated storage files are written t o or copied from

Isolated Storage Explorer Example

Accessing SD Cards

External Storage (SD Card) •

Windows Phone 8 devices support SD cards

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App can discover what files are stored on a storage card •

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Must declare the ID_CAP_REMOVABLE_STORAGE capability in the application manifest file Cannot write files - Access is Read Only Can only open file types for which your app has registered a file association in WMAppManifest.xml

Declare a File Association to WMAppManifest.xml •

You can only open files for which you have declared a File Association in WMAppManifest.xml

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Edit WMAppManifest.xml using the XML editor, not the Manifest editor

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Add a FileTypeAssociation element inside the Extensions element The Extensions element must follow immediately after the Tokens element Note that the ContentType attribute on the FileType element is required •

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