Delphi 2009之TStringBuilder類[6]: Equals

unit Unit1;

interface
uses
　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 判斷對象是否相同

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 都沒有產生新的對象, 只是指向了 sb1

procedure 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.