Ajax in ASP.net Ajax in ASP.net

AJAX Tutorial AJAX = Asynchronous JavaScript and XML. AJAX is not a new programming language, but a new way to use existing standards. AJAX is the art of exchanging data with a server, and updating parts of a web page - without reloading the whole page.

How AJAX Works

The controls provided by ASP.NET for having AJAX functionality are: 1. 2. 3. 4. 5.

ScriptManager ScriptManagerProxy UpdatePanel UpdateProgress Timer

ScriptManager The ScriptManager control is a non-visual component on the page. This control is required on each page that needs to have AJAX features implemented on it. The main functionality of a ScriptManager control is to push Microsoft AJAX framework code to the client side when the page is being rendered. This control can be thought of as the agent which will write the JavaScript required on the client side to facilitate AJAX functionality.There should be only one ScriptManager control on the page that needs AJAX functionality.

ScriptManagerProxy Consider a situation where there is a master page and content page and both need AJAX functinalities functionalities. Since there could be only one ScriptManager on the page, adding a ScriptManager control in these scenarios will result in two ScriptManager controls on the page. So to handle such conditions, the ScriptManagerProxy control can be used. ScriptManagerProxy should be used on content pages that have master pages containing a ScriptManager control. It can also be used inside UserControls when the page containing the UserControl already has the ScriptManager control.

UpdatePanel This is a container control that contains other ASP.NET controls. This control defines a region that is capable of making partial page updates. We can add various server controls inside an UpdatePanel and this controls inside the UpdatePanel will communicate to the server irrespective of the page's postback.

UpdateProgress If the operation is time consuming then we can provide the user feedback by using the UpdateProgress control inside the UpdatePanel. We can add a simple UpdateProgress control to make the user aware of the fact that some processing is being done by the page right now.

Timer There might be some scenarios where we want to update a particular portion of the page after some time duration irrespective of user action. To achieve this, we can use the Timer control.