procedure TForm1.Button2Click(Sender: TObject);
var
  MyStream:TMemoryStream;
begin
  IdAntiFreeze1.OnlyWhenIdle:=False;//设置使程序有反应.
  MyStream:=TMemoryStream.Create;
  try
    //下载我站点的一个ZIP文件
    IdHTTP1.Get('http://www.138soft.com/download/Mp3ToExe.zip',MyStream); 
  except//INDY控件一般要使用这种try..except结构.
    Showmessage('网络出错!');
    MyStream.Free;
    Exit;
  end;
  MyStream.SaveToFile('c:\Mp3ToExe.zip');
  MyStream.Free;
  Showmessage('OK');
end;

procedure TForm1.IdHTTP1WorkBegin(Sender: TObject; AWorkMode: TWorkMode;
  const AWorkCountMax: Integer);
begin
  ProgressBar1.Max:=AWorkCountMax;
  ProgressBar1.Min:=0;
  ProgressBar1.Position:=0;
end;

IdHTTP1的Get还有一种形式就是获取字符串：例如，上面的程序可以改写成：
procedure TForm1.Button1Click(Sender: TObject);
var
  MyStr:String;
begin
  IdAntiFreeze1.OnlyWhenIdle:=False;//设置使程序有反应.
  try
    MyStr:=IdHTTP1.Get('http://www.138soft.com/default.htm');
  except
    Showmessage('网络出错!');
    Exit;
  end;
  Showmessage(MyStr);
end;