gridview中导出EXCEL功能

protected void Button5_Click(object sender, EventArgs e)
        {
            if (GridView1.Rows.Count > 0)
            {
                //调用导出方法  
              ExportGridViewForUTF8(GridView1,"computer.xls");
            }
            else
            {
              // obo.Common.MessageBox.Show(this, "没有数据可导出，请先查询数据!");
            } 




        }

        /// <summary>  
        /// 重载，否则出现“类型“GridView”的控件“GridView1”必须放在具有 runat=server 的窗体标... ”的错误  
        /// </summary>  
        /// <param name="control"></param>  
        public override void VerifyRenderingInServerForm(Control control)
        {
            //base.VerifyRenderingInServerForm(control);  
        }

        /// <summary>  
        /// 导出方法  
        /// </summary>  
        /// <param name="GridView"></param>  
        /// <param name="filename">保存的文件名称</param>  
        private void ExportGridViewForUTF8(GridView GridView, string filename)
        {

            string attachment = "attachment; filename=" + filename;

            Response.ClearContent();
            Response.Buffer = true;
            Response.AddHeader("content-disposition", attachment);

            Response.Charset = "UTF-8";
            Response.ContentEncoding = System.Text.Encoding.GetEncoding("UTF-8");
            Response.ContentType = "application/ms-excel";
            System.IO.StringWriter sw = new System.IO.StringWriter();

            HtmlTextWriter htw = new HtmlTextWriter(sw);
            GridView.RenderControl(htw);

            Response.Output.Write(sw.ToString());
            Response.Flush();
            Response.End();

        }