unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, StdCtrls;type  TForm1 = class(TForm)    Button1: TButton;    Button2: TButton;    procedure Button1Click(Sender: TObject);    procedure Button2Click(Sender: TObject);  private    { Private declarations }  public    { Public declarations }  end;  {继承 TForm1 的类: TMyForm}  TMyForm = class(TForm1)     procedure Button1Click(Sender: TObject);  end;var  Form1: TForm1;  //声明 TForm1 的实例  MyForm1: TMyForm;  //声明 TMyForm 的实例implementation{$R *.dfm}//Form1 上有两个按钮, Button1: 弹出信息; Button2: 创建并显示 MyForm1procedure TForm1.Button1Click(Sender: TObject);begin  ShowMessage('TForm1');end;procedure TForm1.Button2Click(Sender: TObject);begin  MyForm1 := TMyForm.Create(nil);  MyForm1.Show;end;{ TMyForm }//TMyForm1 被创建后, 应该和 TForm1 一摸一样;//Button2: 会继续创建并弹出新的 TMyForm1//Button1: 会弹出两条信息, 因为继承了一条procedure TMyForm.Button1Click(Sender: TObject);begin  inherited;  //继承 Button1 原有的功能  ShowMessage('TMyForm');end;end.