How to avoid flicker while handling WM_ERASEBKGND in Windows dialog

Try adding the following line to your OnInitDialog function:

    ModifyStyle(0, WS_CLIPCHILDREN, 0);

Assuming that "FillSolidRect" is the erase of your background then return TRUE from the WM_ERASEBKGND.

To do the double buffering that you are almost doing in your code fragment, you will need to use CreateCompatibleBitmap and select that into your memDC.