Cancels a pending asynchronous operation.
Assembly: System (in System.dll)
When you call , your application still receives the completion event associated with the operation. For example, when you call to cancel a DownloadStringAsync operation, if you have specified an event handler for the DownloadStringCompleted event, your event handler receives notification that the operation has ended. To learn whether the operation completed successfully, check the Cancelled property on the base class of DownloadDataCompletedEventArgs in the event data object passed to the event handler.
If no asynchronous operation is in progress, this method does nothing.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.