using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Runtime.Serialization;

using System.Text;

using System.Threading.Tasks;

using System.Xml;

​

namespace ConsoleApplication2

{

    class Program

    {

        public static void Main(string[] args)

        {

            var a = new SomeOtherClass();

            a.MyProperty.Bar = "this is bar";

            a.MyProperty.Foo = "this is foo";

            a.MyProperty.AnotherProperty = "another property";

            string encoded = a.MyProperty.SerializeBase64();

            Console.WriteLine(encoded);

            Console.ReadLine();

            var b = MyAbstractBase.DeserializeBase64(encoded);

            Console.WriteLine(b.Bar);

            Console.WriteLine(b.Foo);

            var c = b as SomeOtherClass.MyDerivedClass;

            Console.WriteLine(c.AnotherProperty);

            Console.ReadLine();

        }

    }

​

    [DataContract]

    [KnownType(typeof(SomeOtherClass.MyDerivedClass))]

    public abstract class MyAbstractBase

    {

        [DataMember]

        public string Foo { get; set; }

​

        [DataMember]

        public abstract string Bar { get; set; }

​

        public string SerializeBase64()

        {

            // Serialize to a base 64 string

            byte[] bytes;

            long length = 0;

            MemoryStream ws = new MemoryStream();

            DataContractSerializer serializer = new DataContractSerializer(this.GetType(), new List<Type>() { typeof(SomeOtherClass.MyDerivedClass) });

            XmlDictionaryWriter binaryDictionaryWriter = XmlDictionaryWriter.CreateBinaryWriter(ws);

            serializer.WriteObject(binaryDictionaryWriter, this);

            binaryDictionaryWriter.Flush();

            length = ws.Length;

            bytes = ws.GetBuffer();

            string encodedData = bytes.Length + ":" + Convert.ToBase64String(bytes, 0, bytes.Length, Base64FormattingOptions.None);

            return encodedData;

        }

​

        public static MyAbstractBase DeserializeBase64(string s)

        {

            int p = s.IndexOf(':');

            int length = Convert.ToInt32(s.Substring(0, p));

            // Extract data from the base 64 string!

            byte[] memorydata = Convert.FromBase64String(s.Substring(p + 1));

            MemoryStream rs = new MemoryStream(memorydata, 0, length);

            DataContractSerializer serializer = new DataContractSerializer(typeof(MyAbstractBase), new List<Type>() { typeof(SomeOtherClass.MyDerivedClass) });

            XmlDictionaryReader binaryDictionaryReader = XmlDictionaryReader.CreateBinaryReader(rs, XmlDictionaryReaderQuotas.Max);

            return (MyAbstractBase)serializer.ReadObject(binaryDictionaryReader);

        }

    }

​

    public class SomeOtherClass

    {

        public MyDerivedClass MyProperty { get; set; }

​

        public SomeOtherClass()

        {

            MyProperty = new MyDerivedClass();

        }

​

        [DataContract]

        public class MyDerivedClass : MyAbstractBase

        {

            [DataMember]

            public override string Bar { get; set; }

​

            [DataMember]

            public string AnotherProperty { get; set; }

        }

    }

}

​