Closing All Windows On A Desktop

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2 total messages Started by dln Thu, 01 May 2003 02:16

#16710

Author: dln
Date: Thu, 01 May 2003 02:16

17 lines
2104 bytes

I'm curious if anybody knows how the Windows Task Manager (Win2K, XP) kills
a window when the "End Process" button is clicked?  The reason I ask is I've
written an application which attempts to close all windows on the desktop by
calling DestroyWindow, passing the handle of the window to be closed as the
function's parameter.  For the most part, this works.  However, the instance
of Windows Explorer which controls the Windows shell will not close,
regardless of what API call I use.  In addition to DestroyWindow, I've tried
posting/sending a WM_QUIT and WM_CLOSE message to the window.  The WM_QUIT
does nothing (the icons on the desktop might blink a bit as if they're being
refreshed, but not much else), and the WM_CLOSE causes the "Are you sure you
want to log off?" dialog to appear (and that's not the behavior I desire).
The Windows Task Manager on the other hand, will kill any instance of
Explorer outright (regardless of whether it controls the desktop shell or
not), so it appears to use a function call that I'm not aware of to kill the
window.  Does anybody know how this is accomplished?

Thanks.

Re: Closing All Windows On A Desktop

#16711

Author: Remy Lebeau (TeamB)
Date: Thu, 01 May 2003 03:37

52 lines
2858 bytes

"dln" <dnadon@nospam.austin.rr.com> wrote in message
news:3eb081aa@newsgroups.borland.com...
> I'm curious if anybody knows how the Windows Task
> Manager (Win2K, XP) kills a window when the "End
> Process" button is clicked?

It first attempts to send a simple WM_CLOSE command to the various windows
of the process.  If the process fails to respond to the message at all (such
as during a hangup), then the TaskManager brute-forces the process to
terminate via TerminateProcess().

> the instance of Windows Explorer which controls the
> Windows shell will not close, regardless of what API
> call I use.

You can't shut down the shell that way.  Why would you want to?  What
exactly are you trying to accomplish?  It almost should like you're trying
to brute-force Windows to terminate.  If so, you are going about it
completely wrong.  You should be using the ExitWindows/Ex() function for
that instead.

> In addition to DestroyWindow, I've tried posting/sending a
> WM_QUIT and WM_CLOSE message to the window.

That is the preferred way to go whenever possible.

> The WM_QUIT does nothing (the icons on the desktop
> might blink a bit as if they're being refreshed, but not much else)

That's probably caosed by the shell reloading itself after you try to shut
it down.  You cannot shut down the shell manually.  Only Windows can do
that, and only during an actual system shutdown.

> and the WM_CLOSE causes the "Are you sure you want to
> log off?" dialog to appear

As it should.

> (and that's not the behavior I desire).

Well, that's the behavior you're going to get.

> The Windows Task Manager on the other hand, will
> kill any instance of Explorer outright (regardless of whether
> it controls the desktop shell or not)

Wrong.  It does not shut down the shell.  That would effective kill Windows
itself.


Gambit

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