asp.net 控件 导出 excel

//导出EXCEL
protected void btnDaoChu_Click(object sender, EventArgs e)
{
HttpContext.Current.Response.Clear();
HttpContext.Current.Response.Buffer = true;
HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode("XXX表") + new Random().Next() + ".xls");
HttpContext.Current.Response.Charset = "UTF-8";
HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.Default;
HttpContext.Current.Response.ContentType = "application/ms-excel";
System.IO.StringWriter tw = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter(tw);

GridView1.AllowPaging = false;
BindGrd();
GridView1.RenderControl(hw);
HttpContext.Current.Response.Write(tw.ToString());
HttpContext.Current.Response.End();

GridView1.AllowPaging = true;
BindGrd();

}
public override void VerifyRenderingInServerForm(Control control)
{

// Confirms that an HtmlForm control is rendered for

}