Knowledge Base

PRB: Top Level Window Does Not Receive WM_ENDSESSION Messages

Article ID: 197630

Article Last Modified on 7/11/2005


APPLIES TO


This article was previously published under Q197630

SYMPTOMS

On Windows NT, the top-level window in an application that has called AllocConsole does not receive the WM_QUERYENDSESSION and WM_ENDSESSION messages.

CAUSE

The Windows NT shutdown process examines each process to determine if it is a console or GUI process. If any application has created a console using AllocConsole, the shutdown routine "sees" the application as a console application and does not send the WM_QUERYENDSESSION and WM_ENDSESSION messages.

RESOLUTION

This problem can be worked around by calling SetConsoleCtrlHandler to install a console handler routine. This handler routine is called by the system in response to certain events. The two events of interest in this case are CTRL_EVENT_LOGOFF and CTRL_EVENT_SHUTDOWN.

STATUS

This behavior is by design and has been present at least since Windows NT version 3.1.

Additional query words: kbDSupport

Keywords: kbprb kbwndw KB197630