catch (Exception ex)
        {
            Response.Write("error.aspx?ErrorMsg=" + ex.Message.Replace("<br>", "").Replace("\n", "") + "&ErrorUrl=" + Request.Url.ToString().Replace("<br>", "").Replace("\n", ""));
            
        }

//这段代码是我网上找的，如果有不对的地方，指高手指出
void Application_Error(object sender, EventArgs e) 
    {
        Exception ex = Server.GetLastError().GetBaseException();

        string errorTime = "发生时间：" + DateTime.Now.ToString();
        string errorAddress = "发生异常页：" + Request.Url.ToString();
        string errorInfo = "异常信息：" + ex.Message;
        string errorSource = "错误源：" + ex.Source;
        string errorTrace = "堆栈信息：" + ex.StackTrace;
        Server.ClearError();

        System.IO.StreamWriter writer = null;
        try
        {
            lock (this)
            {
                //写入日志 
                string year = DateTime.Now.Year.ToString();
                string month = DateTime.Now.Month.ToString();
                string day = DateTime.Now.Day.ToString();
                string path = string.Empty;
                string filename = DateTime.Now.ToString("yyyyMMdd") + ".txt";
                path = Server.MapPath("~/Error/") + year + month + day;
                if (!System.IO.Directory.Exists(path))
                {
                    System.IO.Directory.CreateDirectory(path);
                }
                System.IO.FileInfo file = new System.IO.FileInfo(path + "/" + filename);
                writer = new System.IO.StreamWriter(file.FullName, true);//文件不在则创建，true表示追加
                writer.WriteLine("用户IP:" + Request.UserHostAddress);
                writer.WriteLine(errorTime);
                writer.WriteLine(errorAddress);
                writer.WriteLine(errorInfo);
                writer.WriteLine(errorSource);
                writer.WriteLine(errorTrace);
                writer.WriteLine("-------------------------------------------------------");
               

            }
        }
        finally
        {
            if (writer != null)
            {
                writer.Close();
            }
        }
        Server.Transfer("errorpage.aspx"); //跳转到显示友好错误的页面


    }

catch (Exception ex)
        {
            Response.Write("../../error.aspx?ErrorMsg=" + ex.Message.Replace("<br>", "").Replace("\n", "") + "&ErrorUrl=" + Request.Url.ToString().Replace("<br>", "").Replace("\n", ""));
            
        }