Re: Property Sheet (please help)

From:

"Scott McPhillips [MVP]" <org-dot-mvps-at-scottmcp>

Newsgroups:

microsoft.public.vc.mfc

Date:

Fri, 20 Jul 2007 10:00:52 -0400

Message-ID:

<O7idnRuVeNK0XT3bnZ2dnUVZ_t6onZ2d@comcast.com>

vorange wrote:

Hello,

I have a problem which I have not been able to solve for a
whole 2 days. I have a dialog program but I changed it to launch a
modal property sheet instead of a dialog. I have added property pages
(each page as a separate class) to this property sheet successfully.
The property sheet has a Cancel button at the bottom.

In the property sheet I have a worker thread. If I do not access
functions in the pages of the property sheet, I am able to exit the
thread just fine. But if I am running something in a page, then I am
not able to exit the thread successfully. It just stalls the app.

You can call your own functions and access your own variables from a
secondary thread (subject to providing any required synchronization),
but you may not call any MFC CWnd-related functions from a secondary
thread, directly or indirectly. This is a design limitation of MFC.
Access CWnd-related functions only from the thread that created the CWnd.

In practice this means you can do data manipulation in the secondary
thread, but updating the window must be done from the primary thread.
Use custom messages from the thread to the window to request the main
thread to do window updates, as explained here:
http://vcfaq.mvps.org/mfc/index.htm

--
Scott McPhillips [MVP VC++]