using Newtonsoft.Json;

using System;

public class Program

{

    private static JsonSerializerSettings jsonSerializerSettings = new JsonSerializerSettings

    {

        TypeNameHandling = TypeNameHandling.All

    };

​

    public static void Main()

    {

        var person = new Person

        {

            Name = "John Doe",

            Age = 42

        } as IPerson;

        var serialized = JsonConvert.SerializeObject(person, jsonSerializerSettings);

        Console.WriteLine(serialized);

        try

        {

            var person2 = JsonConvert.DeserializeObject(serialized,

                //@"{""$type"":""Person, abcdefgh.exe"",""Name"":""John Doe""}",

                jsonSerializerSettings) as Person;

            Console.WriteLine(person2);

            Console.WriteLine(person2.Age);

        }

        catch (Exception ex)

        {

            Console.WriteLine($"{ex.GetType().Name}: {ex.Message}");

        }   

    }

}

​

public class Person : IPerson

{

    public string Name { get; set; }

    public int Age { get; set; }

}

​

public interface IPerson 

{

    string Name { get; set; }

}