Re: ON_EVENT and Threads

From:

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

Newsgroups:

microsoft.public.vc.mfc

Date:

Mon, 30 Mar 2009 10:22:54 -0400

Message-ID:

<OBKpGMUsJHA.4876@TK2MSFTNGP02.phx.gbl>

What kind of thread did you create? A "worker" thread won't work because it
is not event-driven. You need a thread class derived from CWinThread and
started like... AfxBeginThread(RUNTIME_CLASS(CMyWinThread)

If the dialog and the control are both created in the same thread then there
should not be any problem receiving the events in the dialog. To avoid any
cross-thread dependencies make sure the dialog's parent window is NULL. The
dialog should be created in your CWinThread-derived class InitInstance.

"Geoff Cohen" <GeoffCohen@discussions.microsoft.com> wrote in message
news:C91E05E2-D474-4842-A071-A910630576E3@microsoft.com...

Using VS2008
I'm using some 3rd party Active-X controls in my application.
The code that accesses the controls is implemented using standard code
generated by Visual Studio, with a CDialog-derived class containing the
controls. The controls do not in fact have a UI, and the dialog is not
visible. When the Dialog is created in the application's InitInstance()
all
works fine.

However because some of the controls' methods are a bit slow (one handles
serial interfaces), I wanted to put their operation in another thread.
So I create a separate CWinThread to create the dialog. The application
communicates with the Dialog using PostMessage, to avoid (some) threading
issues. Everything works as expected - except that the controls' events
are
no longer received by the Dialog (the events are invoked by hardware).
Does ON_EVENT only work in the main thread? Is there another strategy
which
can allow the controls' methods to execute in another thread?

--
Scott McPhillips [VC++ MVP]