unit1.pas

演示Delphi如何实现对象克隆

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    mmo1: TMemo;
    btn1: TButton;
    btn2: TButton;
    dlgFont1: TFontDialog;
    procedure btn1Click(Sender: TObject);
    procedure btn2Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
//    FOriginalFont: TFont;
    FOriginalFont: TPersistent;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.btn1Click(Sender: TObject);
begin
  if dlgFont1.Execute then
    mmo1.Font := dlgFont1.Font;
end;

procedure TForm1.btn2Click(Sender: TObject);
begin
  mmo1.Font := TFont(FOriginalFont);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  mmo1.Clear;
  mmo1.Lines.Add('对象克隆');
  FOriginalFont := TFont.Create;
  FOriginalFont.Assign(mmo1.Font);

end;

end.