WCF反序列化，不会调用构造函数，如何解决类的初始化问题

   [DataContract]
    public class MyDataType
    {
        [DataMember]
        private List<int> nVal = new List<int>();
        public MyDataType()
        {
            nVal.Add(12);
        }

        [OnDeserializing]
        void BeginInit(StreamingContext sc)
        {
            Console.WriteLine("same to begin Constructor");
        }

        [OnDeserialized]
        void EndInit(StreamingContext sc)
        {
            Console.WriteLine("same to end Constructor");
        }

        [DataMember]
        public int InitMemberData
        {
            get { return 0; }
            set {
                object obj = this;
                Console.WriteLine("InitMemberData: set.");
            }
        }

        private int intv;
        [DataMember]
        public int INT
        {
            get
            {
                return intv;
            }
            set
            {
                Console.WriteLine("INT: set.");
                if(nVal == null)
                    intv = value;
            }
        }
        string _str;
        [DataMember]
        public string STRING
        {
            get { return _str; }
            set {
                Console.WriteLine("STRING: set.");
                _str = value; 
            }
        }
        long _long;
        [DataMember]
        public long LONG
        {
            get { return _long; }
            set 
            {
                Console.WriteLine("LONG: set.");
                _long = value; 
            }
        }
       
    }