I'm working on a Win32 GUI app using plain Win32 API (no MFC or .NET). The issue I'm having is making controls appear transparent. I've come up with a method which works for most things, in Windows Vista+ I do this in the WndProc:
In Windows XP, I do this in the WndProc:
HBRUSH hbr = (HBRUSH)DefWindowProc(hDlg, message, wParam, lParam);
Now this works for most of the controls, however I get a transparent background on the label on the top of a group box control which draws the group box line through the text. I started working towards a case for just group boxes but I'm sure that this is a problem which must have been solved before and I don't want to go re-inventing the wheel.
Is there a tried and tested method for making controls appear transparent?