首页 / 软件开发 / Delphi / Delphi 2009之TStringBuilder类[6]: Equals

Delphi 2009之TStringBuilder类[6]: Equals2012-02-15 cnblogs 万一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 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.