Delphi 实现无窗口移动（发WM_NCHITTEST消息计算，然后再发WM_SYSCOMMAND消息，带参数SC_DRAGMOVE）

procedure imgListMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);

private

 procedure WMNCHITTEST(var Msg: TWMNCHITTEST); message WM_NCHITTEST;

procedure TfrmStartHit.WMNCHITTEST(var Msg: TWMNCHITTEST);

const

  cOffset = ;

var

  vPoint: TPoint;

begin

  inherited;

  vPoint := ScreenToClient(Point(Msg.XPos, Msg.YPos));

  if PtInRect(Rect(, , cOffset, cOffset), vPoint) then

    Msg.Result := HTTOPLEFT

  else if PtInRect(Rect(Width - cOffset, Height - cOffset, Width, Height), vPoint) then

    Msg.Result := HTBOTTOMRIGHT

  else if PtInRect(Rect(Width - cOffset, , Width, cOffset), vPoint) then

    Msg.Result := HTTOPRIGHT

  else if PtInRect(Rect(, Height - cOffset, cOffset, Height), vPoint) then

    Msg.Result := HTBOTTOMLEFT

  else if PtInRect(Rect(cOffset, , Width - cOffset, cOffset), vPoint) then

    Msg.Result := HTTOP

  else if PtInRect(Rect(, cOffset, cOffset, Height - cOffset), vPoint) then

    Msg.Result := HTLEFT

  else if PtInRect(Rect(Width - cOffset, cOffset, Width, Height - cOffset), vPoint) then

    Msg.Result := HTRIGHT

  else if PtInRect(Rect(cOffset, Height - cOffset, Width - cOffset, Height), vPoint) then

    Msg.Result := HTBOTTOM;

end;

procedure TfrmStartHit.imgListMouseDown(Sender: TObject;

  Button: TMouseButton; Shift: TShiftState; X, Y: Integer);

const

  SC_DRAGMOVE = $F012;

begin

  if (Button = mbLeft) then

  begin

    ReleaseCapture;

    (Self as TControl).Perform(WM_SYSCOMMAND, SC_DRAGMOVE, );

  end;

end;

http://blog.csdn.net/yanjiaye520/article/details/6736069