我怎样拖动image使得整个窗体移动？

Question

//declare in public
procedure wmnchittest(var vMsg : TMessage);message wm_nchittest;
//implementation
procedure TForm1.wmnchittest(var vMsg: TMessage);
begin
  inherited;
  if vMsg.result = htclient then
     vMsg.result := htcaption;
end;

Answer 1

procedure TForm1.Image1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  ReleaseCapture;
  Form1.Perform(WM_SYSCOMMAND, $f012, 0);
end;

Answer 2

不过 鼠标在image上 移动时不会产生WM_nchittest消息