User`s guide

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WinHLLAPICancelAsyncRequest( )
This function cancels an outstanding WinHLLAPIAsync( )-based request.
int WinHLLAPICancelAsyncRequest(HANDLE hAsyncTaskID,WORD
wFunction)
An asynchronous task previously initiated by issuing one of the WinHLLAPIAsync( ) functions can
be canceled prior to completion by issuing the WinHLLAPICancelAsyncRequest( ) function and
specifying the asynchronous task ID as returned by the initial function in the hAsyncTaskID parameter
and the WinHLLAPI function number.
Parameter Type Description
hAsyncTaskID HANDLE Specifies the asynchronous task to be
canceled.
wFunction WORD Specifies the function number to be
canceled.
The return value specifies whether the original asynchronous request was canceled. It is zero if the
request was canceled; otherwise it is on of the following return codes:
WHLLINVALID Indicates that the specified asynchronous task ID was
invalid.
WHLLALREADY The asynchronous routine being canceled has already
completed.
Should an attempt to cancel an existing asynchronous WinHLLAPIAsync( ) routine fail with an error
code of WHLLALREADY, it can be for one of 2 reasons. Firstly, the original routine has already
completed and the application has dealt with the resultant message. Secondly, the original routine has
already completed but the resultant message is still waiting in the application window queue.
See also: WinHLLAPICancelAsyncRequest( )
Syntax
Returns
Remarks