初学者的简单问题，耽误路过的人一小会儿

Question

unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;type
  TForm1 = class(TForm)
    GroupBox1: TGroupBox;
    RadioButton1: TRadioButton;
    RadioButton2: TRadioButton;
    procedure RadioButton1Click(Sender: TObject);
    procedure RadioButton2Click(Sender: TObject);
    TControlClass = class of TControl;//书上说在这里加上这样一句
  private
    { Private declarations }
    ClassKind:TControlClass;//然后加上这样一句
    CpNum:integer;//和这样一句
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.RadioButton1Click(Sender: TObject);
begin
classkind:=tedit;
end;procedure TForm1.RadioButton2Click(Sender: TObject);
begin
classkind:=tbutton;
end;end.
//然后在窗体Event事件页，双击OnMouseDown右边下拉框，输入一段代码，可是一点下拉框就弹出
//expected':'but'='found
//请问这是怎么回事

Answer 1

试一下将那句写到TForm1类的外面：
type
  TControlClass = class of TControl;
  TForm1 = class(TForm)
    GroupBox1: TGroupBox;
  //......