Re: Drawing disappears when window dragged

From:

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

Newsgroups:

microsoft.public.vc.mfc

Date:

Sat, 17 Feb 2007 14:26:59 -0500

Message-ID:

<OXFHKnsUHHA.4076@TK2MSFTNGP05.phx.gbl>

zaku_so wrote:

Thanks.
But now the drawings flash once and disappear.
I moved the code for drawing to after CDialog::OnPaint().

Originally the drawing region is a static picture rectangle.
After I changed the type to frame, flashing does not occur anymore.
What's the reason behind? Is that the solid rectangle is drawn after my
drawings, so that they are covered immediately?

void CPiezoDlg::OnPaint()
{

    if (IsIconic())
    {
        CPaintDC dc(this); // device context for painting
                                ...
    }
    else
    {
        CDialog::OnPaint();
        //Moved codes for drawing here
    }
}

Yes, the static picture is a child window and is drawn on top of the
dialog. Drawing in a static rectangle is much better than trying to
paint on the dialog. If you want to draw in a static rectangle then you
do the drawing in a class you derive from CStatic. It will have its
own OnPaint.

1. Derive a class from CStatic.
2. Create a CStatic control member variable in the dialog. Change it to
your CStatic-derived class.
3. Add WM_PAINT/OnPaint to your class and do the painting in there.

--
Scott McPhillips [VC++ MVP]