BKI_DichVuMatDat.NghiepVu.HopDong.f001_import_hop_dong.check_ma_hop_dong C# (CSharp) Method

        private bool check_ma_hop_dong(DataTable ip_dt, string ma)
        {
            var list_ma = (from DataRow dr in ip_dt.Rows
                           where dr["MA_HOP_DONG"] != null
                           select dr["MA_HOP_DONG"]).ToList();
            foreach (var item in list_ma)
            {
                if (String.IsNullOrEmpty(item.ToString()))
                {
                    continue;
                }
                if (item.ToString() == ma)
                {
                    return false;
                }
            }
            return true;
        }