Represents the method that handles asynchronous events such as application events. This delegate is called at the start of an asynchronous operation.
[Visual Basic] <Serializable> Public Delegate Function Sub BeginEventHandler( _ ByVal sender As Object, _ ByVal e As EventArgs, _ ByVal cb As AsyncCallback, _ ByVal extraData As Object _ ) As IAsyncResult [C#] [Serializable] public delegate IAsyncResult BeginEventHandler( object sender, EventArgs e, AsyncCallback cb, object extraData ); [C++] [Serializable] public __gc __delegate IAsyncResult* BeginEventHandler( Object* sender, EventArgs* e, AsyncCallback* cb, Object* extraData );
[JScript] In JScript, you can use the delegates in the .NET Framework, but you cannot define your own.
Parameters [Visual Basic, C#, C++]
The declaration of your event handler must have the same parameters as the BeginEventHandler delegate declaration.
- The source of the event.
- An EventArgs that contains the event data.
- The delegate to call when the asynchronous method call is complete. If cb is a null reference (Nothing in Visual Basic), the delegate is not called.
- Any additional data needed to process the request.
The IAsyncResult that represents the result of the BeginEventHandler operation.
Platforms: Windows 2000, Windows XP Professional, Windows Server 2003 family
Assembly: System.Web (in System.Web.dll)