Retrieve the focused control in another process

To retrieve the window handle of the currently focused control can easily be done by GetFocs() if it is part of your own process.

For controls in other processes windows you need to attach the input processing mechanism of the thread with the focus to that your own thread. Function AttachThreadInput will attach or detach depending on the last parameter.

You may use this code:

	function GetFocussedWindow(ParentWnd:HWnd):HWnd; var OtherThread, Buffer : DWord; begin OtherThread := GetWindowThreadProcessID(ParentWnd, @Buffer); if AttachThreadInput(GetCurrentThreadID, OtherThread, true) then begin Result := GetFocus; AttachThreadInput(GetCurrentThreadID, OtherThread, false); end else Result:=0; end;