What is the WIN32 API WM_REFLECT message for?

Question

I can't find documentation for it, even on MSDN...

Answer 1

Some reasoning here:
http://www.tech-archive.net/Archive/VC/microsoft.public.vc.language/2005-08/msg00589.html

Answer 2

It's not Win32; it's MFC. Ordinarily, a Win32 control raises events by sending a message to its parent window. However, if you've got your own class derived from one of MFC's wrappers (e.g. you've wrapped CTreeCtrl with CMyFunkyTreeCtrl), you might want to handle these events in the derived class.

MFC uses these reflection messages to bounce the event back to the class itself, where your derived class can see them.

Look at TN062: Message Reflection for Windows Controls (MFC) for more information.