web c# 內容輸出為Excel

UsersDAL usDAL = new UsersDAL();
        DataTable dt = usDAL.GetDataTable(where);
        StringWriter sw = new StringWriter();
        sw.WriteLine("自動編號"t姓名"t電話"temail"t地址"tQQ"t身份證"t中獎等級"t中獎日期"t狀態"tIP");
        foreach (DataRow dr in dt.Rows)
        {
            string state = (bool.Parse(dr["state"].ToString()) == true) ? "審核" : "未審核";
            sw.WriteLine(dr["uid"] + ""t" + dr["name"] + ""t" + dr["phone"] + ""t" + dr["email"] + ""t" + dr["adress"] + ""t" + dr["qq"] + ""t" + dr["idcard"] + ""t" + dr["rate"] + ""t" + dr["luckday"].ToString() + ""t" + state + ""t" + dr["ip"]);
        }
        sw.Close();
        Response.AddHeader("Content-Disposition", "attachment; filename=data.xls");
        Response.ContentType = "application/ms-excel";
        Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
        Response.Write(sw);

        Response.End();

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string fileName = page.Server.MapPath(System.DateTime.Now.ToString("yyyyMMddhhmmss") + System.DateTime.Now.Millisecond.ToString() + (new Random()).Next(0, 1000).ToString() + ".xls");
            FileStream fs = new FileStream(fileName, FileMode.CreateNew, FileAccess.Write, FileShare.None);
            StreamWriter swFromFile = new StreamWriter(fs, System.Text.Encoding.GetEncoding("gb2312"));
            
           swFromFile.WriteLine(fileValue);//要寫入的資料         

            swFromFile.Flush();
            swFromFile.Close();

            page.Response.Clear();
            page.Response.ClearHeaders();
            page.Response.Buffer = false;
            page.Response.ContentType = "Application/x-msexcel";
            page.Response.AppendHeader("Content-Disposition", "attachment:filename=" + page.Server.UrlEncode(System.IO.Path.GetFileName(fileName)));
            page.Response.WriteFile(fileName);
            page.Response.Flush();
            File.Delete(fileName);
            page.Response.End();