DataContract Hierarchy ; How WCF manage relationship on DataMembers? My Experience

Hi , 

I tried out  few  combinations to  expolore , how DataMember are exposed to client . 

First is  I used   base class with Serilizable attribute. And I implented service as below 

    [Serializable]
    public class BaseData
    {
        [DataMember]
        public int ID { get; set; }
    }
    [DataContract]
    public class SubData:BaseData 
    {
        [DataMember]

        public int ID { get; set; }
    }
}

 Surprisngly at the client side ,  I  am getting two ID , ID1 ( I know , why I am getting two ID because , I am not overriding the ID field). But I am getting ID property exposed for the subclass .

            Service1Client proxy = new Service1Client();
            SubData obj = new SubData();
            obj.ID = 9;
            obj.ID1 = 10; 
            Console.WriteLine(obj.ID);
            Console.WriteLine(obj.ID1);
            Console.ReadKey(true);

Second , when I changed the class like below 

[Serializable]
    public class BaseData
    {
        [DataMember]
        public  virtual int ID { get; set; }
    }
    [DataContract]
    public class SubData:BaseData 
    {
        [DataMember]

        public  override  int ID { get; set; }
    }

I am not getting ID for either of the class.  where as I am getting Idk_backingField. I am not sure whether, it is substitution of ID property  ?

            Service1Client proxy = new Service1Client();
            SubData obj = new SubData();
            BaseData baseobj = new BaseData();
            baseobj.IDk__BackingField = 10;
            obj.IDk__BackingField = 10;
            Console.WriteLine(obj.IDk__BackingField);
           Console.WriteLine(baseobj.IDk__BackingField);
            Console.ReadKey(true);
                     

3rd  I tried  

I changed classes as

 [DataContract]
    public class BaseData
    {
        [DataMember]
        public  virtual int ID { get; set; }
    }
    [DataContract]
    public class SubData:BaseData 
    {
        [DataMember]

        public  override  int ID { get; set; }
    }

 and at the client side , I am getting ID property exposed for both of the classes . see the client code below. 

 Service1Client proxy = new Service1Client();
            SubData obj = new SubData();
            BaseData baseobj = new BaseData();
            obj.ID = 9;
            baseobj.ID = 10;
       
            Console.WriteLine(obj.ID);
           Console.WriteLine(baseobj.ID );
            Console.ReadKey(true);

So Id for both of the classes are exposed. 

Now coming to  usual class definition 

 [DataContract(Namespace="http://localhost/KnownType")]
    [KnownType(typeof(SubData))]
    public class BaseData
    {
        [DataMember]
        public  virtual int ID { get; set; }
    }
    [DataContract(Namespace = "http://localhost/KnownType")]
    public class SubData:BaseData 
    {
        [DataMember]

        public  override  int ID { get; set; }
    }

 

At client side both Id is exposed .

            Service1Client proxy = new Service1Client();
            SubData obj = new SubData();
            BaseData baseobj = new BaseData();
            obj.ID = 9;
            baseobj.ID = 10;
            
       
            Console.WriteLine(obj.ID);
           Console.WriteLine(baseobj.ID );
            Console.ReadKey(true);
                     

Its really funny right ? How WCF is managing it . any way , we know after reading this blog the best 

way to go with DataContract Hierarchy