自動產生編號 DATAGRID

private void dg_Data_ItemDataBound(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
{
if(e.Item.ItemIndex!=-1)
{
e.Item.Cells[0].Text=(this.dg_Data.CurrentPageIndex*this.dg_Data.PageSize+e.Item.ItemIndex+1).ToString();
}
}