正在运行的线程中的静态控件的重绘窗口

Question

I have a CStatic control that I would like to set its text at runtime (computing a Fibonacci number)

Class TXT:public CStatic
{
  private:
    CString m_str;
  public:
    SetText(const CString& str)
    {
       m_str=str;
       RedrawWindow();
    }
////other methods OnPaint etc 
}
//someclass that contains 
{
////....
TXT m_res;
///....

}
UINT threadProc(LPVOID lp)
{
   //computing Fibonacci
   p->m_res.SetText("resultTXT"); 
}

My problem is the output string result overwrites each other; the text's not erased once a new output comes.

WHat else should I do to fix this problem ?

Answer 1

My guess is that you are creating the window in the main thread (the GUI thread), but then calling functions on that window from the worker thread. That would be against the rules since windows have affinity to the thread on which they are created.

Make sure that all your API calls that use the window handle are made from the main thread. Note that SendMessage() calls are marshalled onto the correct thread, but in any case, for performance reasons, they are also better to be send from the main thread.