Sys.Application

The execution of each asp.net ajax page is controlled by an application object that is intstantiated in the body of the library. Whenever an asp.net ajax page is loaded in the browser, an instance of Sys._Application class is promptly created and assigned to the Sys.Application object: Sys.Application = new Sys._Application();

In additional, each asp.net ajax page is injected with the following script code:

This code is placed immediately after the closing tag of the of the page's form, and it commands the loading of any script files registered for loading with the page's script manager. Sys._Application class derives from Compnent and is the entry point point in the page hierachy to locate client-side components either bound to server controls or programmatically added to the application.

Member	Description
addComponent	Adds the specified Microsoft AJAX library component to the page hierarchy
beginCreateComponents	Starts adding new Microsoft AJAX library components to the page
endCreateComponents	Ends adding new Microsoft AJAX library components to the page
findComponent	Looks up the specified Microsoft AJAX library component in the page
getComponents	Gets the list of Microsoft AJAX library components found in the page
initialize	Ensures that all referenced script files are loaded
notifyScriptLoaded	Called by script files to notify the application object that the script has been successfully loaded
queueScriptReference	Queues a new script reference for loading
removeComponent	Removes the specified component from the page hierarchy

Vents in the page lifetime

Event	Description
Init	Occurs when the page is first initialized
Load	Occurs when the page is loaded
loadTimedOut	Occurs when the loading step takes too much time to complete
scriptLoadFailed	Occurs when one script fails to load for whatever reason
Unload	Occurs when the page is unloaded

Client Page Life-cycle Events