AsyncCallback Delegate
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
References a method to be called when a corresponding asynchronous operation is completed.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Syntax
Public Delegate Sub AsyncCallback ( _
ar As IAsyncResult _
)
public delegate void AsyncCallback(
IAsyncResult ar
)
Parameters
- ar
Type: System..::.IAsyncResult
The result of the asynchronous operation.
Remarks
Use an AsyncCallback delegate to process the results of an asynchronous operation in a separate thread. The AsyncCallback delegate represents a callback method that is called when the asynchronous operation is completed. The callback method takes an IAsyncResult parameter, which is subsequently used to obtain the results of the asynchronous operation.
Version Notes
Windows Phone
Asynchronous delegate calls, specifically the BeginInvoke and EndInvoke methods, are not supported in Windows Phone. If you attempt to invoke delegates asynchronously, the application throws TargetInvocationException instead of NotSupportedException.
Version Information
Windows Phone OS
Supported in: 8.1, 8.0, 7.1, 7.0
Platforms
Windows Phone