导出txt直接让用户选择下载~

Response.Clear();

       Response.AddHeader("content-disposition", "attachment;filename=FileName.txt");

       Response.Charset = "gb2312";

       Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");

       Response.ContentType = "application/vnd.txt";

       StringBuilder sb = new StringBuilder(Regex.Replace(mobiles, ",", "\r\n"));

       System.IO.StringWriter stringWrite = new System.IO.StringWriter(sb);

       System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);           

       Response.Write(stringWrite.ToString());

       Response.End();