WM_CAPTURECHANGED (Compact 2013)
This message is sent to the window losing the capture.
WM_CAPTURECHANGED hwndNewCapture = (HWND)lParam;
Handle to the window gaining the mouse capture.
An application should return zero if it processes this message.
A window receives this message even if the window calls ReleaseCapture itself. An application should not attempt to set the mouse capture in response to this message.
When a window receives this message, the window should redraw itself to reflect the new mouse-capture state, if necessary.