/// <summary>

        /// base64 解码Excel下载

        /// </summary>

        /// <param name="excelContent"></param>

        /// <param name="strFileName"></param>

        public void BidExcelDown(string excelContent, string strFileName) {

            Response.Clear(); //清空无关信息

            Response.Buffer= true; //完成整个响应后再发送

            Response.Charset = "GB2312";//设置输出流的字符集-中文

            Response.ContentEncoding = System.Text.Encoding.GetEncoding("UTF-8");//设置输出流的字符集

            Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(strFileName + ".xls", System.Text.Encoding.UTF8));//追加头信息

            Response.ContentType = "application/octet-stream";//输出流的Excel类型

            byte[] outputb = Convert.FromBase64String(excelContent); //解码
           //如果编码是字符串就无需这样解码了

           //二进制的所以输出的时候一定要记得带上下面这句

            Response.BinaryWrite(outputb);//输出二进制的流

            Response.End();//输出停止

        }