sourceUri
The source URI to download.
destinationFileName
The destination file name to download to.
destinationData
The destination stream information.
error
Any error that occurred during the asynchronous operation.
cancelled
A value that indicates whether the asynchronous operation was canceled.
userState
The optional user-supplied state object that is used to identify the task that raised the download operation.
This constructor initializes the members of this class as follows: