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);  end;var  Form1: TForm1;implementation{$R *.dfm}//TStringBuilder.Equals 判断对象是否相同procedure TForm1.Button1Click(Sender: TObject);var  sb1,sb2: TStringBuilder;  b: Boolean;begin  sb1 := TStringBuilder.Create('abc');  sb2 := TStringBuilder.Create('abc');  b := sb1.Equals(sb2);  ShowMessage(BoolToStr(b, True)); {True}  sb2.Length := 0;  b := sb1.Equals(sb2);  ShowMessage(BoolToStr(b, True)); {False}  sb1.Free;  sb2.Free;end;//此例中的 sb2 都没有产生新的对象, 只是指向了 sb1procedure TForm1.Button2Click(Sender: TObject);var  sb1,sb2: TStringBuilder;begin  sb1 := TStringBuilder.Create('abc');  sb2 := sb1;  sb1.Append('123');  ShowMessage(sb2.ToString); {abc123}  sb2 := sb1.Replace('123', ' 123');  ShowMessage(sb1.ToString); {abc 123}  ShowMessage(sb2.ToString); {abc 123}  ShowMessage(BoolToStr(sb2.Equals(sb1), True)); {True}  sb1.Free;end;end.