procedure TWinControl.WMParentNotify(var Message: TWMParentNotify);

begin

  with Message do

    if (Event <> WM_CREATE) and (Event <> WM_DESTROY) or

      not DoControlMsg(Message.ChildWnd, Message) then inherited;

end;

function DoControlMsg(ControlHandle: HWnd; var Message): Boolean;

var

  Control: TWinControl;

begin

  DoControlMsg := False;

  Control := FindControl(ControlHandle);

  if Control <> nil then

    with TMessage(Message) do

    begin

      Result := Control.Perform(Msg + CN_BASE, WParam, LParam);

      DoControlMsg := True;

    end;

end;