public partial class Form3 : Form
{
  //緩存類
  System.Web.Caching.Cache cache;
  public Form3()
  {
   InitializeComponent();
   string SQL = "select top 1000 * from infomation";
   DataTable datatable = DBHelper.GetDataTable(SQL, ConnType.Menu);
   dataGridView1.DataSource = datatable;
   cache = System.Web.HttpRuntime.Cache;
   cache.Insert("infomation", datatable);
  }
  private void button1_Click(object sender, EventArgs e)
  {
   if (cache != null) {
    DataTable table = cache["infomation"] as DataTable;
    dataGridView2.DataSource = table;
   }   
  }
}