How to serialize/deserialize an object loaded from another assembly?

After poking around some more (i.e. googling the answer), I was able to resolve this. Here is the modified code:

Interfaces.cs (from a referenced assembly, Interfaces.dll)

public interface ISomeInterface
{
 ISettings Settings { get; set; }
}

public interface ISettings
{
 DateTime StartDate { get; }
}

SomeClass.cs (from a referenced assembly, SomeClass.dll)

public class SomeClass : ISomeInterface
{
 private MySettings settings = new Settings();

 public ISettings Settings
 {
  get { return (ISettings)settings; }
  set { settings = value as MySettings; }
 }
}

[Serializable]
public class MySettings : ISettings
{
 private DateTime dt;

 public MySettings() { dt = DateTime.Now; }

 public DateTime StartDate
 {
  get { return startFrom; }
  internal set { startFrom = value; }
 }
}

Serialization is done with:

public void SerializeState(string filename, ProgramState ps)
{
 Stream s = File.Open(filename, FileMode.Create);
 BinaryFormatter bFormatter = new BinaryFormatter();
 bFormatter.AssemblyFormat =
    System.Runtime.Serialization.Formatters.FormatterAssemblyStyle.Simple;
 bFormatter.Serialize(s, ps);
 s.Close();
}

And deserialization with:

public ProgramState DeserializeState(string filename)
{
 if (File.Exists(filename))
 {
  ProgramState res = new ProgramState();
  Stream s = File.Open(filename, FileMode.Open);
  BinaryFormatter bFormatter = new BinaryFormatter();
  bFormatter.AssemblyFormat =
    System.Runtime.Serialization.Formatters.FormatterAssemblyStyle.Simple;
  bFormatter.Binder = new MyBinder(); // MyBinder class code given below
  try
  {
   res = (ProgramState)bFormatter.Deserialize(s);
  }
  catch (SerializationException se)
  {
   Debug.WriteLine(se.Message);
  }
  s.Close();
  return res;
 }
 else return new ProgramState();
}

This class was added. This is the binder for the binary formatter:

internal sealed class MyBinder : SerializationBinder
{
 public override Type BindToType(string assemblyName, string typeName)
 {
  Type ttd = null;
  try
  {
   string toassname = assemblyName.Split(',')[0];
   Assembly[] asmblies = AppDomain.CurrentDomain.GetAssemblies();
   foreach (Assembly ass in asmblies)
   {
    if (ass.FullName.Split(',')[0] == toassname)
    {
     ttd = ass.GetType(typeName);
     break;
    }
   }
  }
  catch (System.Exception e)
  {
   Debug.WriteLine(e.Message);
  }
  return ttd;
 }
}

Do you want to (de)serialize using binary format? If no you may use the following:

P.S. This is not an solution but some kind of workaround.

Some assembly

public interface ISomeInterface { ISettings Settings { get; set; } }

public interface ISettings : ISerializable
{
    DateTime StartDate { get; }
}

public class SerializeHelper<T>
{
    public static void Serialize(string path, T item)
    {
        var serializer = new XmlSerializer(typeof(T));
        using (TextWriter textWriter = new StreamWriter(path, false, Encoding.UTF8))
        {
            serializer.Serialize(textWriter, T item);
        }
    }
}

SerializeHelper.Serialize(@"%temp%\sample.xml", instanceOfISomeInterface);

Some other assembly

public interface ISomeOtherInterface
{
ISettings Settings { get; set; }
}

public class DeSerializeHelper<T>
{
    public static T Deserialize(string path)
    {
   T instance = default(T);
   var serializer = new XmlSerializer(typeof(TestData));
   using (TextReader r = new StreamReader(path, Encoding.UTF8))
   {
      instance = (T)serializer.Deserialize(r);
   }
   return instance;
    }
}

ISomeOtherInterface instance = DeSerializeHelper.Deserialize<SomeOtherInterfaceImplementation>(@"%temp%\sample.xml")