Cancels a pending asynchronous operation.
Assembly: System.Net (in System.Net.dll)
When you call the method, your application still receives the completion event associated with the operation. For example, if you call to cancel a DownloadStringAsync operation and 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 of the AsyncCompletedEventArgs for the relevant completed event handler.
If you cancel a string download operation and you check the Result property of the
DownloadStringCompletedEventArgs object, an exception will occur.
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.