private void DataGrid1_SortCommand(object source, System.Web.UI.WebControls.DataGridSortCommandEventArgs e)
  {
   DataSet ds=new DataSet();
   ds=DB.getdataset ("select * from mytab");
   DataView dv=ds.Tables [0].DefaultView ;
   dv.Sort=e.SortExpression ;
   DataGrid1 .DataSource =dv;
   DataGrid1 .DataBind ();
  
  }

实现双向排序...

if(ViewState["order"]==null)
   {
    ViewState["order"]="asc";
   }
   else
   {
    if(ViewState["order"].ToString ()=="asc")
    {
     ViewState["order"]="desc";

    }
    else
    {
     ViewState["order"]="asc";
    }

   }
   SqlConnection mycon=DB.creatcon ();
   SqlDataAdapter da=new SqlDataAdapter ("select * from student order by studentid desc ",mycon);
   DataSet ds=new DataSet() ;
   da.Fill (ds,"tabnew");
   DataView dv=ds.Tables [0].DefaultView ;
   dv.Sort =e.SortExpression+" "+ViewState["order"].ToString();
   DataGrid1.DataSource =dv;
   DataGrid1 .DataBind ();