从Gridview中获取全部数据

在ASP.NET  2 .0中将GridView中的数据全部导出到Excel中，请参考下述代码（以手动绑定数据源为例）：
Defualt.aspx中，添加一个GridView控件
   < form id = " form1 "  runat = " server " >
     < div >
         < asp:GridView ID = " GridView1 "  runat = " server "  AllowPaging = " true "  OnPageIndexChanging = " paging " >
         </ asp:GridView >
     </ div >
     < asp:Button ID = " Button1 "  runat = " server "  OnClick = " Button1_Click<