protected void ExportExcel(DataGrid dtgList, string strFileName)
        {
            DataTable dt = (DataTable)this.Session["GridToExcel"];
            if (dt==null) return;

            Response.Clear(); 
            Response.Buffer = true; 
            Response.Charset = "gb2312";
            Response.AppendHeader("Content-Disposition", "online; filename=" + this.GetFileName(strFileName) + ".xls");
            Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
            Response.ContentType = "application/ms-excel";
            EnableViewState = false;
            System.Globalization.CultureInfo myCItrad = new System.Globalization.CultureInfo("zh-CN",true);
            System.IO.StringWriter oStringWriter = new System.IO.StringWriter(myCItrad); 
            System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
            dtgList.AllowPaging = false;
        //    dtgList.DataSource = dt;
        //    dtgList.DataBind();
            dtgList.RenderControl(oHtmlTextWriter); 
            Response.Write(oStringWriter.ToString());
            Response.Buffer = false; 
            Response.End();
        }