please someone correct me very.
i readed several texts about doing a child control transparent, but i can't put it to work correctly. my last working code was with Regions, but not always works :(
i have readed, too, about bitmap brushes, but i need more information and advices. i even have readed about WM_PRINTCLIENT(for print the parent DC to child DC), but without sucess too :(

Have you seen these pages?

Custom controls:
https://msdn.microsoft.com/en-us/library/windows/desktop/bb775501%28v=vs.85%29.aspx

Custom draw:
https://msdn.microsoft.com/en-us/library/windows/desktop/bb761817%28v=vs.85%29.aspx

sorry. but i continue with same problem :(
how can i build an irregular shapes child controls without using Regions?

https://msdn.microsoft.com/en-us/library/windows/desktop/dd162814(v=vs.85).aspx