public static DateTime?GetLastRecordEnterTimeByCarNo(string parkingID, string cardNo, out string ErrorMessage) { if (parkingID.IsEmpty()) { throw new ArgumentNullException("parkingID"); } if (cardNo.IsEmpty()) { throw new ArgumentNullException("cardNo"); } IParkIORecord factory = ParkIORecordFactory.GetFactory(); return(factory.GetLastRecordEnterTimeByCarNo(parkingID, cardNo, out ErrorMessage)); }