C# Language Serialization Binder


Example

The binder gives you an opportunity to inspect what types are being loaded in your application domain

Create a class inherited from SerializationBinder

class MyBinder : SerializationBinder
{
    public override Type BindToType(string assemblyName, string typeName)
    {
        if (typeName.Equals("BinarySerializationExample.Item"))
            return typeof(Item);
        return null;
    }
}

Now we can check what types are loading and on this basis to decide what we really want to receive

For using a binder, you must add it to the BinaryFormatter.

object DeserializeData(byte[] bytes)
{
    var binaryFormatter = new BinaryFormatter();
    binaryFormatter.Binder = new MyBinder();

    using (var memoryStream = new MemoryStream(bytes))
        return binaryFormatter.Deserialize(memoryStream);
}

The complete solution

using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;

namespace BinarySerializationExample
{
    class MyBinder : SerializationBinder
    {
        public override Type BindToType(string assemblyName, string typeName)
        {
            if (typeName.Equals("BinarySerializationExample.Item"))
                return typeof(Item);
            return null;
        }
    }

    [Serializable]
    public class Item
    {
        private string _name;

        public string Name
        {
            get { return _name; }
            set { _name = value; }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            var item = new Item
            {
                Name = "Orange"
            };

            var bytes = SerializeData(item);    
            var deserializedData = (Item)DeserializeData(bytes);
        }

        private static byte[] SerializeData(object obj)
        {
            var binaryFormatter = new BinaryFormatter();
            using (var memoryStream = new MemoryStream())
            {
                binaryFormatter.Serialize(memoryStream, obj);
                return memoryStream.ToArray();
            }
        }

        private static object DeserializeData(byte[] bytes)
        {
            var binaryFormatter = new BinaryFormatter
            {
                Binder = new MyBinder()
            };

            using (var memoryStream = new MemoryStream(bytes))
                return binaryFormatter.Deserialize(memoryStream);
        }
    }
}