public partial class GridViewToExcel : System.Web.UI.Page
{
        GridView gridToExport = null;

 protected void Page_Load(object sender, EventArgs e)
    {

    }



    /// <summary>
    /// 必须override这个方法，否则会报错
    /// 
    /// "Control 'ctl00_MainContent_Gridview1' of type 'GridView' must be placed
    /// inside a form tag with runat=server", 
    /// even though you have the supposedly missing form tag.
    /// 
    /// </summary>
    /// <param name="control"></param>
    public override void VerifyRenderingInServerForm(Control control)
    {
        //base.VerifyRenderingInServerForm(control);
    }

    protected void btnExport_Click(object sender, EventArgs e)
    {
        gridToExport = gvwEmployee;
    }

    protected override void Render(HtmlTextWriter writer)
    {
        if (gridToExport as GridView != null)
        {
            ExportGridToExcel(gridToExport, "test.xls");
        }
        base.Render(writer);
    }
   

    private void ExportGridToExcel(GridView grid, string filename)
    {
        // 检查是否有文件名
        if (string.IsNullOrEmpty(filename))
        {
            throw new ArgumentException("Export filename is required");
        }
        // 检查是否是excel格式
        if (!filename.EndsWith(".xls"))
        {
            filename += ".xls";
        }
        grid.AllowPaging = false; 　// 禁止分页
        grid.AllowSorting = false;　// 禁止排序
        grid.DataBind();            // 绑定数据

        StringWriter tw = new StringWriter();
        HtmlTextWriter hw = new HtmlTextWriter(tw);

        Response.Clear();
        Response.ContentType = "application/vnd.ms-excel";
        Response.AddHeader("content-disposition", "attachment;filename=" + filename);
        Response.Charset = string.Empty;
        Page.EnableViewState = false;
        grid.RenderControl(hw);
        Respo