导出为excel

protected void Button1_Click(object sender, EventArgs e)
    {
        StringBuilder sb = new StringBuilder();
        StringWriter sw = new StringWriter(sb);
        HtmlTextWriter htw = new HtmlTextWriter(sw);

        Page page = new Page();
        HtmlForm form = new HtmlForm();
        GridView1.EnableViewState = false;
        form.Controls.Add(GridView1);  
        page.Controls.Add(form);
         

        page.RenderControl(htw);

        Response.Clear();
        Response.Buffer = true;
        Response.ContentType = "application/vnd.ms-excel";
        Response.AddHeader("Content-Disposition", "attachment;filename=data.xls");
        Response.Charset = Encoding.Default.ToString();
        Response.ContentEncoding = Encoding.Default;
        Response.Write(sb.ToString());
        Response.End();

    }