Win32 doesn't send mouse events to my window, only its parent. why?

I have a window that's a CHILD window of another window. For r开发者_StackOverfloweasons beyond me, NC_HITTEST never gets called on it, no mouse events are called for it (but rather reach its parent window).

Why is that? I want that child window to process his own mouse clicks.

NC_HITTEST is not likely a message you want to be catching for mouse events. You want to be catching WM_MOUSEMOVE, WM_LBUTTONDOWN, etc...