Represents the method that will handle the MethodNameCompleted event of an asynchronous operation.
Assembly: System (in System.dll)
[HostProtectionAttribute(SecurityAction.LinkDemand, SharedState = true)] public delegate void AsyncCompletedEventHandler( Object sender, AsyncCompletedEventArgs e )
When you create an delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event-handler method is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see Events and Delegates.
For an asynchronous method, called MethodName, in your component, you will have a corresponding MethodNameCompleted event, and an optional MethodNameCompletedEventArgs class.
For a component that supports multiple concurrent invocations of its asynchronous methods, the client can supply a unique token, or task ID, to distinguish which asynchronous task is raising particular events. The client's can read the AsyncCompletedEventArgs.UserState property to determine which task is reporting completion. Your implementation should use the System.ComponentModel.AsyncOperationManager to create an System.ComponentModel.AsyncOperation that associates the client's task IDs with pending asynchronous tasks.
The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: SharedState. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.
For a code example of the delegate, see the example in the System.ComponentModel.AsyncCompletedEventArgs class.
.NET FrameworkSupported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0
.NET Framework Client ProfileSupported in: 4, 3.5 SP1
Portable Class LibrarySupported in: Portable Class Library
.NET for Windows Store appsSupported in: Windows 8
.NET for Windows Phone appsSupported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1
Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)