asp.net导出excel

运行时可以导出，但是发布后就不行了，各位大侠有没有什么好的解决方法啊？
我的代码如下：
HttpResponse resp;
            resp = Page.Response;
            resp.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
            resp.AppendHeader("Content-Disposition", "attachment;filename=ll.xls");
            resp.ContentType = "application/ms-excel";
            this.EnableViewState = false;  
            string colHeaders = "", Is_item = "";
            //int i = 0;
            if (ds.Tables.Count != 0 && ds.Tables[0].Rows.Count != 0)
            {
                int count = ds.Tables[0].Rows.Count;
                colHeaders = "学号";
                resp.Write(colHeaders + "\t"););
                colHeaders="姓名";
                resp.Write(colHeaders + "\t");
                colHeaders = "性别";
                resp.Write(colHeaders + "\t");
                colHeaders = "体育班信息";
                resp.Write(colHeaders + "\t");
                colHeaders = "行政班";
                resp.Write(colHeaders + "\t");
                colHeaders  = "年级";
                resp.Write(colHeaders + "\t");
                colHeaders = "考试成绩";
                resp.Write(colHeaders + "\n");
                if (type == 0)
                {
                    for (int i = 0; i < count; i++)
                    {
                        //for (int j = 0; j < 7; j++)
                        //{
                        //    excel.Cells[i + 2, j + 1] = ds.Tables[0].Rows[i][j].ToString();
                        //}
                        Is_item  = ds.Tables[0].Rows[i][0].ToString();
                        resp.Write(Is_item + "\t");
                        Is_item  = ds.Tables[0].Rows[i][1].ToString();
                        resp.Write(Is_item + "\t");
                        Is_item = ds.Tables[0].Rows[i][2].ToString();
                        resp.Write(Is_item + "\t");
                        Is_item = ds.Tables[0].Rows[i][7].ToString();
                        resp.Write(Is_item + "\t");
                        Is_item= ds.Tables[0].Rows[i][3].ToString();
                        resp.Write(Is_item + "\t");
                        Is_item = ds.Tables[0].Rows[i][4].ToString();
                        resp.Write(Is_item + "\t");
                        Is_item = ds.Tables[0].Rows[i][5].ToString();
                        resp.Write(Is_item + "\n");
                    }
                }
                else
                {
                    for (int i = 0; i < count; i++)
                    {
                        for (int j = 0; j < 7; j++)
                        {
                            Is_item = ds.Tables[0].Rows[i][j].ToString();
                            if (j != 6)
                            {
                                resp.Write(Is_item + "\t");
                            }
                            else
                            {
                                resp.Write(Is_item + "\n");
                            }
                        }
                    }
                }
                cook.Expires = DateTime.Now;
                Response.Cookies.Add(cook);
            }
            //Is_item = "kk";
            //resp.Write(Is_item);
            resp.End(); --------------------编程问答--------------------

protected void Button1_Click(object sender, EventArgs e)

        {

            string filename = "理赔查看";

            Export("application/ms-excel", filename);

        }

        private void Export(string fileType, string filename)

        {

            Response.Clear();

            Response.Buffer = true;

            Response.Charset = "gb2312";

            Response.ContentEncoding = System.Text.Encoding.UTF7;

            Response.AppendHeader("content-disposition", "attachment;filename=\"" + System.Web.HttpUtility.UrlEncode(filename, System.Text.Encoding.UTF8) + ".xls\"");

            //Response.AppendHeader("Content-Disposition","attachment;filename="+System.Web.HttpUtility.UrlEncode(filename,System.Text.Encoding.UTF8)+".xls");

            Response.ContentType = fileType;

            this.EnableViewState = false;

            StringWriter tw = new StringWriter();

            HtmlTextWriter hw = new HtmlTextWriter(tw);

            GridView1.RenderControl(hw);

            Response.Write(tw.ToString());

            Response.End();

        }

        public override void VerifyRenderingInServerForm(System.Web.UI.Control control)

        {



            //base.VerifyRenderingInServerForm(control);





        }

这是一段可以正常使用的代码

--------------------编程问答-------------------- ？
？？？？？？？？？？？？？？？？？？？？？？ --------------------编程问答-------------------- 学习了。。。。。。。。。。

补充：.NET技术 ,  其他语言