The dialog event handler onLBDragging stops reporting when moved outside of its control area but it returns the IDC of the control it's currently hovering over. Therefore this does not seem like intended behaviour, especially when you consider that onLBDrop is setup to be able to allow cross control dragging as well (and actually functions correctly). So I believe that onLBDragging is broken and should actually be firing when outside of its control and when over other controls.

Unless there is some way to allow the EH to continue firing when outside its controls area or to extend the control's area without destroying its styling?