IAsyncResult Interface

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Represents the status of an asynchronous operation.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)


Public Interface IAsyncResult
public interface IAsyncResult

The IAsyncResult type exposes the following members.


Name Description
AsyncState Gets a user-defined object that qualifies or contains information about an asynchronous operation.
AsyncWaitHandle Gets a WaitHandle that is used to wait for an asynchronous operation to complete.
CompletedSynchronously Gets a value that indicates whether the asynchronous operation completed synchronously.
IsCompleted Gets a value that indicates whether the asynchronous operation has completed.



The IAsyncResult interface is implemented by classes containing methods that can operate asynchronously. It is the return type of methods that initiate an asynchronous operation, such as IsolatedStorageFileStream..::.BeginRead, and is passed to methods that conclude an asynchronous operation, such as IsolatedStorageFileStream..::.EndRead. An IAsyncResult is also passed to the method that is invoked by an AsyncCallback delegate when an asynchronous operation completes.

An object that supports the IAsyncResult interface stores state information for an asynchronous operation, and provides a synchronization object to allow threads to be signaled when the operation completes.

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0


Windows Phone

See Also


System Namespace