Re: Trapping Alt-F4

From:
"David Ching" <dc@remove-this.dcsoft.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
Tue, 25 Sep 2007 13:16:11 -0700
Message-ID:
<80eKi.401$ih1.41@nlpi068.nbdc.sbc.com>
"Gerry Murphy" <gerry_murphy@comcast.net> wrote in message
news:uIbXFX6$HHA.4324@TK2MSFTNGP02.phx.gbl...

I have a weird bug I'm trying to fix.
This is an older MDI application, 16-bit actually.

The problem occurs when a modeless dialog, that's basically
hosting a progress bar, does not have the focus and the user hits Alt-F4
and causes a GPF.

I thought this would be easy, just trap the message in
PreTranslateMessage()
and be done. Except it's not working.

The callstack window indicates the code is failing in a GetDlgItem() call
in a function of the dialog called UpdateStatus(), which does pretty much
what
its name suggests and is called a lot.


Perhaps you are overriding the wrong PreTranslateMessage(). I would think
it needs to be in the class for whatever window has the focus (not the
modeless dialog).

Alt-F4 generates a WM_SYSCOMMAND with SC_CLOSE message. It should be
handled by your CMainFrame. Instead of trapping Alt+F4, I would trap this
WM_SYSCOMMAND message so the user can't close your app using the system menu
either.

-- David

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