.NET, C#: How to add a custom serialization attribute that acts as ISerializable interface

Question

I am doing some serialization of db linq objects, which contain EntitySet and EntityRef classes.

I found a pretty easy way to deal with serialization of these classe

Answer 1

Yes, you can do this by implementing ISerializationSurrogate and ISurrogateSelector interfaces.

Something like this:

[AttributeUsage(AttributeTargets.Class)]
public class SerializeLinqEntities : Attribute
{
}

public class LinqEntitiesSurrogate : ISerializationSurrogate
{
    public void GetObjectData(
      object obj, SerializationInfo info, StreamingContext context)
    {
        EntitySerializer.Serialize(this, obj.GetType(), info, context);
    }

    public object SetObjectData(
      object obj, SerializationInfo info,
      StreamingContext context, ISurrogateSelector selector)
    {
        EntitySerializer.Deserialize(obj, obj.GetType(), info, context);
        return obj;
    }
}


/// <summary>
/// Returns LinqEntitySurrogate for all types marked SerializeLinqEntities
/// </summary>
public class NonSerializableSurrogateSelector : ISurrogateSelector
{
    public void ChainSelector(ISurrogateSelector selector)
    {
        throw new NotImplementedException();
    }

    public ISurrogateSelector GetNextSelector()
    {
        throw new NotImplementedException();
    }

    public ISerializationSurrogate GetSurrogate(
      Type type, StreamingContext context, out ISurrogateSelector selector)
    {
        if (!type.IsDefined(typeof(SerializeLinqEntities), false))
        {
            //type not marked SerializeLinqEntities
            selector = null;
            return null;
        }
        selector = this;
        return new LinqEntitiesSurrogate();
    }

}

[SerializeLinqEntities]
public class TestSurrogate
{
    public int Id { get; set; }
    public string Name { get; set; }
}

class Program
{
    static void Main(string[] str)
    {

        var ns1 = new TestSurrogate {Id = 47, Name = "TestName"};
        var formatter = new BinaryFormatter();
        formatter.SurrogateSelector = new NonSerializableSurrogateSelector();

        using (var ms = new MemoryStream())
        {
            formatter.Serialize(ms, ns1);
            ms.Position = 0;

            var ns2 = (TestSurrogate) formatter.Deserialize(ms);
            // Check serialization
            Debug.Assert(ns1.Id == ns2.Id);
            Debug.Assert(ns1.Name == ns2.Name);
        }
    }
}

Answer 2

Unfortunately no, ISerializable is an interface designed to allow you to control the serialization process while the SerializableAttribute is just a marker that says "this class can be serialized". However, you could look into something like PostSharp to add this functionality (take a look at the CompositionAspect).