public override void VerifyRenderingInServerForm(Control control)
    {
        // Confirms that an HtmlForm control is rendered for
    }
    protected void Button1_Click(object sender, EventArgs e)
    { 
        
        Response.Clear();
        //附件打开,注意其扩展名和指定文件类型相符，可以为：.doc .xls .txt .htm
        //Response.AddHeader("content-disposition", "attachment;filename=FileName.xls");
        //XLM文档打开在线打开
        //Response.AddHeader("content-disposition", "FileName.xls");
        Response.AddHeader("content-disposition", "attachment;filename=FileName.xls");
        Response.Charset = "utf-8";
        //指定文件类型 可以为application/ms-excel、application/ms-word、application/ms-txt、application/ms-html 或其他浏览器可直接支持文档
        Response.ContentType = "application/ms-excel";
        System.IO.StringWriter stringWrite = new System.IO.StringWriter();
        System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);
        GridView1.AllowPaging = false;
        BindData(strsql);
        //GridView  表示输gridview数据，你也可以绑定datagrid,或其他支持obj.RenderControl()属性的控件
        GridView1.RenderControl(htmlWrite);
        Response.Write(stringWrite.ToString());
        Response.End();
        GridView1.AllowPaging = true;
        BindData(strsql);
    }