unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); end; var Form1: TForm1; implementation {$R *.dfm} //TStringBuilder 的插入与删除 procedure TForm1.Button1Click(Sender: TObject); var sb: TStringBuilder; begin sb := TStringBuilder.Create; sb.Append('CodeGear 2007'); sb.Insert(Length('CodeGear '), 'Delphi '); ShowMessage(sb.ToString); {CodeGear Delphi 2007} sb.Remove(Length('CodeGear Delphi'), Length(' 2007')); ShowMessage(sb.ToString); {CodeGear Delphi} sb.Insert(sb.Length, ' 2009'); ShowMessage(sb.ToString); {CodeGear Delphi 2009} sb.Free; end; end.