C++ winapi pass mouse clicks on child windows to parent window

Question

I want to handle the clicks on child windows the same as clicks on parent window - how can I do that in winapi?

Currently, I can move the parent window by pressing anywhere on it but not on the child windows, because then it won't move. How can I change that?

Answer 1

Capture the mouse click on the desired child controls(s), and then send a WM_SYSCOMMAND message with SC_DRAGMOVE (0xF012, aka SC_MOVE OR'ed with 2) as the wParam parameter to the parent window. That will invoke a drag operation on the parent window.

This is a widely known trick, and well documented online (just not by Microsoft) if you do a search for SC_DRAGMOVE .

Answer 2

The answer that works:

case WM_NCHITTEST: 
        if (hWnd==parent)
        return HTCAPTION;
        else return HTTRANSPARENT;