private void DownLoadText(string text)
    {
        bool ok = true;
        string fileName;
        fileName = DateTime.Now.ToString("yyyyMMddHHmmss") + ".gbpt";
        try
        {
            Response.ClearHeaders();
            Response.ContentType = "application/zip;";
            Response.Charset = "UTF-8";
            Response.AddHeader("Content-Disposition", string.Format("attachment;filename=\"{0}\"", fileName));
            Response.BinaryWrite(Encoding.Default.GetBytes(text));
        }
        catch (Exception ex)
        {
            ok = false;
            Response.Write("生成文件失败：" + ex.Message + "，请稍后再试。");
            CreateGbpt(fileName, text);
        }
        if (ok)
        {
            Response.End();
        }
    }

#region 把字符串写成文件
    private void CreateGbpt(string fileName, string text)
    {
        bool ok = true;
        string filePath;

        filePath = Server.MapPath(fileName);

        Encoding code = Encoding.GetEncoding("utf-8"); //定义编码

        try
        {
            using (StreamWriter sw = new StreamWriter(filePath, false, code))
            {
                sw.Write(text.Trim());
                sw.Flush();
            }
        }
        catch (DirectoryNotFoundException ex)
        {
            ok = false;
            Response.Write("写入文件出错：" + ex.Message);
        }

        //文件写入成功，下载文件
        if (ok)
        {
            DownLoadFile(fileName);
        }
    }
    #endregion

    #region 下载文件
    private void DownLoadFile(string fileName)
    {
        bool ok = true;
        if (System.IO.File.Exists(Server.MapPath(fileName)))
        {
            try
            {
                Response.ClearHeaders();
                Response.ContentType = "application/zip;";
                Response.Charset = "UTF-8";
                Response.AddHeader("Content-Disposition", string.Format("attachment;filename=\"{0}\"", fileName));
                Response.BinaryWrite(GetFileBytes(fileName));
            }
            catch (Exception ex)
            {
                ok = false;
                Response.Write("文件不能提供下载，请手动点击下载。" + ex.Message);
            }
            if (ok)
            {
                File.Delete(Server.MapPath(fileName));
                Response.End();
            }
            else
            {
                HypFile.NavigateUrl = fileName;
                HypFile.Text = "生成文件：" + fileName + "，请点击下载";
            }
        }
    }
    private byte[] GetFileBytes(string fileName)
    {
        try
        {
            using (System.IO.FileStream fileStream = new System.IO.FileStream(System.Web.HttpContext.Current.Server.MapPath(fileName), System.IO.FileMode.Open, System.IO.FileAccess.Read))
            {
                byte[] bytes = new byte[fileStream.Length];
                fileStream.Read(bytes, 0, (int)fileStream.Length);
                return bytes;
            }
        }
        catch
        {
            return null;
        }
    }
    #endregion