Re: writing to gui from thread

From:
"Ajay Kalra" <ajaykalra@yahoo.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
21 Feb 2007 07:36:02 -0800
Message-ID:
<1172072162.493377.198310@l53g2000cwa.googlegroups.com>
On Feb 19, 3:31 pm, kunal s patel
<kunalspa...@discussions.microsoft.com> wrote:

Hi all,
Here is a part of code:

#include "maindlg.h"

UINT MyThread(LPVOID obj); //thread function definition
class Cmaindlg
{
//this is the class of main gui with a listbox
CListbox m_listbox;

};

#include "sim.h"
#include "maindlg.h"

class sim
{
   //another file
   void proc(); //this function access the gui
   void run();

}

Now when someone press a button in maindlg application i spawn a thread
like this:

UINT MyThread(LPVOID obj)
{
    sim s;
    s.proc();

}

The function proc is defined as

void sim::proc()
{
   Cmaindlg* pmain = (Cmaindlg*) AfxGetMainWnd();
   pmain->m_listbox.AddString("Hi");

}

Now when i try to run this application, i get an assertion error. I am not
able to understand what is going wrong. Can anyone explain me the way out of
it. Basically i want to access the gui objects from thread.

thanks
kunal


I think you have got the crux of the problem from other posters. In
your worker thread, dont call AfxGetMainWnd; instead send window
handle to the thread and use it later when you need it to
PostMessage() using the window handle.

---
Ajay

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