IDATAREADER 与 DATATABLE 读取数据

IDataReader reader = command.ExecuteReader();
int i = 0;
            while (reader.Read() && i < sliderSize)
            {
                int id = Convert.ToInt32(reader["ID"]);
                string pic = reader["PIC"].ToString();
                string title = reader["TITLE"].ToString();
                _rvl.Add(new ADsInfo { ID = id, PIC = pic, TITLE = title });
                i++;
            }

DataTable dt = db.CenterSlidePlayerAd();
DataRow[] rootRows = dt.Select();
foreach (DataRow dr in rootRows)
            {
                int id = Convert.ToInt32(dr["ID"]);
                string pic = dr["PIC"].ToString();
                string title = dr["TITLE"].ToString();
                _rvl.Add(new ADsInfo { ID = id, PIC = pic, TITLE = title });
                if ((++i) > (sliderSize - 1))//取5条广告,sliderSize=5
                    break;
            }