用WCF的DataContract/Data成员序列化对象

我正在尝试序列化我的数据层对象。这些是具有属性、方法和对象集合的复杂对象。

所有的类都继承自一个被序列化的基类。

    [DataContract]
    [KnownType(typeof(Person))]
    [KnownType(typeof(Client))]
    [KnownType(typeof(Professional))]
    [KnownType(typeof(ProfessionalApptHistory))]
    [KnownType(typeof(DailySchedule))]
    [KnownType(typeof(Option))]
    [KnownType(typeof(PersonType))]
    [KnownType(typeof(ProfessionClientInteractionType))]
    [KnownType(typeof(ProfessionalClientInteractions))]
    [KnownType(typeof(ProfessionalCalendar))]
    public abstract class CMBase
    {
        protected designs3_OurTimeEntities _entities = new designs3_OurTimeEntities();
        [DataMember()]
        public abstract bool IsPersisted { get; internal set; }
    }

我有一个person类它也被序列化了

    [DataContract(Name = "Person")]
    [KnownType(typeof(Professional))]
    [KnownType(typeof(Client))]
    public abstract class Person : CMBase
    {
        [DataMember()]
        public int PersonId { get; internal set; }
        [DataMember()]
        public int PersonTypeId { get; set; }
        [DataMember()]
        public string Name { get; set; }
        [DataMember()]
        public string ContactNumber { get; set; }
        [DataMember()]
        public string ImageLocation { get; set; }
        [DataMember()]
        public Bitmap Image { get; internal set; }
        [DataMember()]
        public Guid MembershipUserId { get; internal set; }
        [DataMember()]
        public DateTime? ActivationStartDate { get; internal set; }
        [DataMember()]
        public string Email { get; internal set; }
        [DataMember()]
        public string Zip { get; set; }
        [DataMember()]
        public bool ShowDefaultPage { get; set; }
        [DataMember()]
        public bool IsClient { get; internal set; }
        [DataMember()]        
        public override bool IsPersisted
        {
            get
            {
                if (this.PersonId == 0)
                {
                    return false;
                }
                else
                {
                    return true;
                }
            }
            internal set
            {
                throw new NotImplementedException();
            }
        }

…}

那么这个类没有被序列化

    [DataContract(Name = "Professional")]
    public class Professional : Person
    {
        [DataMember()]
        public DateTime DateStartedInProfession { get; set; }
        [DataMember()]
        public int? ShopId { get; set; }
        [DataMember()]
        public DateTime LastPayment { get; set; }
        [DataMember()]
        public DateTime NextPaymentDate { get; set; }
        [DataMember()]
        public DateTime TerminationDate { get; set; }
        [DataMember()]
        public int? Rating { get; internal set; }
        [DataMember()]
        public bool hasSystemAccess { get; internal set; }
        [DataMember()]
        public List<SaveResult> SaveResults { get; internal set; }
...
}

我还有其他没有被序列化的类，我不知道发生了什么

[DataMember()]
public int? ShopId { get; set; }

[DataMember()]
public Nullable<int> ShopId { get; set; }