GridView导出Excel

        protected void Button1_Click1(object sender, EventArgs e)
        {
            int gid = Convert.ToInt32(Convert.ToInt32(Request["Gid"]));
            StringBuilder sb = new StringBuilder();
            sb.Append("select '编号=cu.UnitName,'姓名'=cu.JPName,'价格'=ct.Price,'时间'=ct.TenderTime");
            sb.Append(" from cms_tenders ct,CMS_UserDetail cu where cu.ID=ct.UserID and ct.generalid="+gid);


            Response.Clear();
            Response.HeaderEncoding = System.Text.Encoding.GetEncoding("gb2312");
            Response.AddHeader("content-disposition", "attachment;filename=编号"+gid+"信息.xls");
            Response.Charset = "gb2312";
            Response.ContentType = "application/vnd.xls";
            Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
            System.IO.StringWriter stringWrite = new System.IO.StringWriter();
            System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);
            //htmlWrite.Encoding = System.Text.Encoding.GetEncoding("gb2312");
            //GridView1.AllowPaging = false;
            //BindData();
            //GridView1.RenderControl(htmlWrite);
            if (DBHelper.ConnectionString == "")
                DBHelper.ConnectionString = ConfigurationManager.AppSettings["DefaultConnectionString"].ToString();
            GridView gv = new GridView();
            //string strSql = "select * from CMS_Content c ,CMS_U_News n where c.GeneralID=n.GeneralID and ModelID=1 ";
            //string strSearch = "";
            //if (PublishDate.Value.Trim() != "")
            //{
            //    strSearch += " and DateCreated>=convert(datetime,'" + PublishDate.Value + "')";
            //}
            //if (txtEndDate.Value.Trim() != "")
            //{
            //    strSearch += " and DateCreated<convert(datetime,'" + txtEndDate.Value + " 23:59:59')";
            //}
            //strSql += strSearch;
            gv.DataSource = DBHelper.ExecuteDataSet(sb.ToString());
            gv.DataBind();
            gv.RenderControl(htmlWrite);
            Response.Write(stringWrite.ToString());

            Response.End();
        }