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.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2