Re: AfxThread question

From:

David Wilkinson <no-reply@effisols.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Fri, 28 Apr 2006 15:00:52 -0400

Message-ID:

<ORi4SYvaGHA.4936@TK2MSFTNGP05.phx.gbl>

kathy wrote:

I have a piece of code:

...
m_data.sThreadType = _T("Client1");
CWinThread* clientThread1 =
AfxBeginThread(ClientThreadFunction,(LPVOID)&m_data);
::Sleep(1);
m_data.sThreadType = _T("Client2");
CWinThread* clientThread2 =
AfxBeginThread(ClientThreadFunction,(LPVOID)&m_data);
...

UINT CDialog_MFC_WorkThread::ClientThreadFunction(LPVOID pParam)
{
    ThreadData* pData = (ThreadData*) pParam;

    CString cs = pData->sThreadType;
    if(cs == _T("Client1"))
        m_CListBox_Client1.AddString(_T("in ClientThreadFunction()"));
    else if(cs == _T("Client2"))
        m_CListBox_Client2.AddString(_T("in ClientThreadFunction()"));
    return 0;
}

it runs OK.

BUT, If I comment out the Sleep(1), I set break point at:
                m_CListBox_Client1.AddString(_T("in
ClientThreadFunction()"));
It never breaks. Why?

kathy:

I'm not quite sure of the answer to your specific question, but you are
manipulating controls in the main thread from the worker thread. This is
a no-no.

Use a custom message to your CDialog_MFC_WorkThreadand with
PostMessage() or SendMessage() to change the thread context, and have
the dialog update the controls in the main thread.

David Wilkinson