偶要做到控件在运行时可以自由拖动，这么搞的：
procedure MyMouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
begin
ReleaseCapture;
(Sender as TControl).Perform(WM_SYSCOMMAND,$F012,0);
end;

procedure TForm1.N11111Click(Sender: TObject);
var
i :integer;
str :string;
begin
for i := 0 to Controlcount -1 do
begin


TMyControl(self.Components[I]).OnMouseDown := MyMouseDown;
end;
end;
为啥TLabel不行呢？偶跟踪了一下，它也激活了MouseDown事件了，可死活都不动。Button、Edit等都好使。