Sample code mtmdi got problem in VS 2019?

Question

I am studying the code VC2010Samples\MFC\advanced\mtmdi
When I run it and Open a new bounce window, I select color -> custom.... It opens a dialog box, but has no response to any mouse click or keyboard type. What is the problem?
I used Visual Studio 2019 community version to compile and link. Anything changed since 2010?

Thanks in advance
dsiyekd

Answer 1

I haven't spent a lot of time looking at this but I think the problem may be related to the cross-thread relationship created between the windows. If you change the code to use the desktop window as the owner of the color dialog (not recommended as a general practice) the hang seems to be resolved.

void CBounceWnd::OnCustomColor()
{
    CColorDialog dlgColor(m_clrBall, 0, GetDesktopWindow());
    if (dlgColor.DoModal() == IDOK)
    {
        m_clrBall = dlgColor.GetColor();
        m_nIDColor = IDM_CUSTOM;
        MakeNewBall();
        Invalidate();
    }
}