没有任何技术含量，只是怕自己忘了命名空间，汗一个！

System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
            sw.Start();
            XmlDataSourceSysMenuMain.Data = SysMenu.GetMenuXMLDataCache(sysUser.Job.ID);
            sw.Stop();
            LiteralLoginname.Text = sw.ElapsedMilliseconds.ToString();