.net中导出到EXCEL

我想在.net中单击按钮（ID：btnGetExcel）导出到EXCEL，我也写了事件，可没反应，请指点下！！！
 private void BindData1()
    {
        GridView1.DataSourceID = "SqlDataSource1";
        SqlDataSource1.SelectCommand = Session["sqlstr"].ToString();
        GridView1.DataBind();    }    protected void Button2_Click(object sender, EventArgs e)
    {
        Response.Clear();
        Response.Buffer = false;
        Response.Charset = "GB2312";
        Response.AppendHeader("Content-Disposition", "attachment;filename=" + DateTime.Now.ToString("yyyyMMddHHmmss") + "QD.xls");
        Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
        Response.ContentType = "application/ms-excel";
        Response.Write("<meta http-equiv=Content-Type content=\"text/html; charset=GB2312\">");
        this.EnableViewState = false;
        System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
        HtmlTextWriter oHtmlTextWriter = new HtmlTextWriter(oStringWriter);
        GridView1.AllowPaging = false;
        BindData1();
        GridView1.RenderControl(oHtmlTextWriter);
        Response.Write(oStringWriter.ToString());
        Response.End();
        GridView1.AllowPaging = true;
        BindData1();
    }