When you create an AsyncCompletedEventHandler 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 AsyncCompletedEventHandler can read the AsyncCompletedEventArgs.UserState property to determine which task is reporting completion. Your implementation should use the AsyncOperationManager to create an AsyncOperation that associates the client's task IDs with pending asynchronous tasks.
Assembly: System (in System.dll)
Assembly Versions: 126.96.36.199, 188.8.131.52
Since: .NET 2.0
The members of System.ComponentModel.AsyncCompletedEventHandler are listed below.
See Also: Delegate