View source for WinCancelShutdown

This function cancels a request for an application to shut down.

==Syntax==
 WinCancelShutdown (hmq, fCancelAlways)

==Parameters==
;hmq (HMQ) - input:Handle of message queue for current thread.
;fCancelAlways (BOOL) - input:Cancellation control.
:;TRUE:No WM_QUIT message should be placed on this queue during system shutdown.
:;FALSE:The applications ignore any outstanding WM_QUIT messages already sent to it, but a message should be sent during other system shutdowns.

==Returns==
;rc (BOOL) - returns:Success indicator.
:;TRUE:Successful completion
:;FALSE:Error occurred.

==Remarks==
On a system shutdown, each message queue normally posts a WM_QUIT message. An application can then handle this message in one of the three ways: 
*Destroy its message queue using WinDestroyMsgQueue (hmq).
*Call WinCancelShutdown (hmq, TRUE) to prevent the current thread's event queue from receiving the WM_QUIT messages when the system is shut down. This does not stop other threads from receiving this message.
*Call WinCancelShutdown (hmq, FALSE) to remove all pending WM_QUIT messages from the current thread's event queue but allow future WM_QUIT messages to be posted. 
Either way, the system can proceed to the next queue.

==Example Code==
<pre>
#define INCL_WINMESSAGEMGR /* Or use INCL_WIN, INCL_PM, Also in COMMON section */
#include <os2.h>

HMQ     hmq;            /*  Handle of message queue for current thread. */
BOOL    fCancelAlways;  /*  Cancellation control. */
BOOL    rc;             /*  Success indicator. */

rc = WinCancelShutdown(hmq, fCancelAlways);
</pre>
This example cancels a shutdown request (WM_QUIT message) and specifies that the message queue will not accept any new WM_QUIT messages.
<pre>
#define INCL_WINMESSAGEMGR  /* Window Message Functions */
#include <os2.h>

HAB   hab,
BOOL  fSuccess;             /* Success indicator        */
HMQ   hmq;                  /* Queue handle             */

hmq      = WinCreateMsgQueue(hab, 0);
fSuccess = WinCancelShutdown(hmq, TRUE);
</pre>

==Related Functions==
*[[WinCreateMsgQueue]]
*[[WinInitialize]] 
*[[WinTerminate]]

==Related Messages==
*[[WM_QUIT]] 

[[Category:Win]]