Re: Worker thread in VC++ 6
"David Wilkinson" <no-reply@effisols.com> wrote in message
news:eWunJXycIHA.5208@TK2MSFTNGP04.phx.gbl...
Maybe this will help:
http://vcfaq.mvps.org/mfc/12.htm
Scott:
I just read this reference, and there are two things in it I don't agree
with:
1. "Your secondary thread will need an hwnd (not a CWnd*) to post to."
This is not necessary. It is perfectly safe to call CWnd::PostMessage() or
CWnd::SendMessage(). This is because these calls wrap ::PostMessage() and
::SendMessage() in a very simple way.
True, but using a CWnd* in a secondary thread is invalid for almost any
other calls. The FAQ is adhering to the letter or the law here, even though
in this one case it would work safely. I think this is advisable for
recommendations to newbies.
2. "To receive and process the message in the main thread code, first
declare your message hander function in the main window's h file. MFC does
not route user-defined messages to views or docs, so the handler must be a
member function of the CMainFrame class (or the main dialog class in a
dialog-based app)."
This is also not necessary. Rather the handler must be in whatever class
that you send or post the message to (need not be the class corresponding
to the main window).
Otherwise the link is a good explanation of how to post or send private
messages.
Also true. But the general solution recommended works in all cases, is
easier to explain, and is more appropriate for newbies when thread shutdown
issues are considered.
Then again, this FAQ is ancient and has fallen into a no-maintenance mode.
--
Scott McPhillips [VC++ MVP]