用ReleaseCapture后不能响应MouseUp

Question

procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  ReleaseCapture;
  SendMessage(Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);
end;procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  ShowMessage('UP');
end;
各位帮忙看看要怎么响应MouseUp

Answer 1

不应该这样用啊
都是先SetCapture
处理完了，再ReleaseCapture