- // coordinate.
- ::ScreenToClient(hWnd, &pt2);
- hWnd = ::ChildWindowFromPointEx(hWnd, pt2, CWP_SKIPINVISIBLE);
+ // coordinate using ChildWindowFromPointEx().
+ for ( ;; )
+ {
+ pt2.x = pt.x;
+ pt2.y = pt.y;
+ ::ScreenToClient(hWnd, &pt2);
+ HWND child = ::ChildWindowFromPointEx(hWnd, pt2, CWP_SKIPINVISIBLE);
+ if ( child == hWnd || !child )
+ break;
+
+ // ChildWindowFromPointEx() only examines the immediate children
+ // but we want to get the deepest (top in Z-order) one, so continue
+ // iterating for as long as it finds anything.
+ hWnd = child;
+ }