类引用示例

http://www.cnblogs.com/del/archive/2007/12/17/1003289.html

 

 ClassRef: TControlClass;  //TControlClass 是 TControl 的类引用

procedure TForm1.FormCreate(Sender: TObject);
begin
  RadioGroup1.Width := 300;
  RadioGroup1.Columns := 3;
  RadioGroup1.Items.Add('Button');
  RadioGroup1.Items.Add('Edit');
  RadioGroup1.Items.Add('Lable');

  RadioGroup1.ItemIndex := 0;
  ClassRef := TButton;
end;

procedure TForm1.RadioGroup1Click(Sender: TObject);
begin
  case RadioGroup1.ItemIndex of
    0: ClassRef := TButton;
    1: ClassRef := TEdit;
    2: ClassRef := TLabel;
  end;
end;