How to Sort the DataTable in asp.net c#

                DataView dv= dt.DefaultView;
                dv.Sort = "ID Desc";
                dataGridView1.DataSource = dv;

Add new Row in DataTable

 DataRow dr1 = dt.NewRow();
                        dr1["Race_item"] = Convert.ToString(ds.Tables[0].Rows[LIntCtr][2].ToString());
                        dr1["PostPosition"] = Convert.ToString(ds.Tables[0].Rows[LIntCtr][3].ToString());
                        dr1["HorseName"] = Convert.ToString(ds.Tables[0].Rows[LIntCtr][44].ToString());
                        dr1["JockeyName"] = Convert.ToString(ds.Tables[0].Rows[LIntCtr][32].ToString());
                        dr1["TodaysTrainer"] = Convert.ToString(ds.Tables[0].Rows[LIntCtr][27].ToString());
                        dr1["HorseRacingTodaysScore"] = allValues;
                        dt.Rows.Add(dr1);