Handling WM_NCPAINT “breaks” DWM glass rendering on Vista/Aero

Question

I am trying to make a window that alternates between having an Aero/Glass and a custom rendered frame (by handling WM_NCPAINT) based on a user setting. (Windows

Answer 1

When toggling between Aero/Glass and your custom rendered frame it you can use the following to explicitly control the non-client area rendering policy:

DWMNCRENDERINGPOLICY policy = DWMNCRP_ENABLED; // DWMNCRP_DISABLED to toggle back
DwmSetWindowAttribute(hwnd, 
                      DWMWA_NCRENDERING_POLICY, 
                      (void*)&policy, 
                      sizeof(DWMNCRENDERINGPOLICY));