using System;

using System.Collections.Generic;

using System.Linq;

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

public class Program

{

    public static void Main()

    {

        string json = @"

        [

          {

            ""FirstName"": ""Jane"",

            ""LastName"": ""Doe"",

            ""Birthday"": ""1988-10-06T00:00:00""

          },

          {

            ""FirstName"": ""Joe"",

            ""LastName"": ""Schmoe"",

            ""Birthday"": null

          }

        ]";

​

        RootModelConverter converter = new RootModelConverter();

        RootModel model = JsonConvert.DeserializeObject<RootModel>(json, converter);

        model.Addresses.Add(new Address

        {

            Id = 1,

            Street = "123 Main Street",

            City = "Birmingham",

            State = "AL",

            PostalCode = "35201",

            Country = "USA"

        });

        foreach (var person in model.People)

        {

            person.AddressId = 1;

        }

​

        json = JsonConvert.SerializeObject(model, Formatting.Indented);

        Console.WriteLine(json);

        Console.WriteLine();

        model = JsonConvert.DeserializeObject<RootModel>(json, converter);

        foreach (var person in model.People)

        {

            Address addr = model.Addresses.FirstOrDefault(a => a.Id == person.AddressId);

            Console.Write(person.FirstName + " " + person.LastName);

            Console.WriteLine(addr != null ? " lives in " + addr.City + ", " + addr.State : "");

        }

    }

}

​

public class RootModelConverter : JsonConverter

{

    public override bool CanConvert(Type objectType)

    {

        return objectType == typeof(RootModel);

    }

​

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)

    {

        JToken token = JToken.Load(reader);

        RootModel model = new RootModel();

        if (token.Type == JTokenType.Array)

        {

            // we have a Version 3 or earlier model, which was just a list of people.

            model.People = token.ToObject<List<Person>>(serializer);

            model.Addresses = new List<Address>();

            return model;

        }

        else if (token.Type == JTokenType.Object)

        {

            // Check that the version is something we are expecting

            string version = (string)token["Version"];  // case sensitive!

            if (version == "4")

            {

                serializer.Populate(token.CreateReader(), model);

                return model;

            }

            else

            {

                throw new JsonException("Unexpected version: " + version);

            }

        }

        else

        {

            throw new JsonException("Unexpected token: " + token.Type);

        }

    }

​

    public override bool CanWrite

    {

        get { return false; }

    }

​

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)

    {

        throw new NotImplementedException();

    }

}

​

public class RootModel

{

    public int Version { get { return 4; } }

    public List<Person> People { get; set; }

    public List<Address> Addresses { get; set; }

}

​

public class Person

{

    public string FirstName { get; set; }

    public string LastName { get; set; }

    public DateTime? Birthday { get; set; }

    public int AddressId { get; set; }

​

    // This property is here to support transitioning from the Version 2 model to Version 3

    [JsonProperty]

    private string Name

    {

        set

        {

            if (value != null)

            {

                string[] parts = value.Split(' ');

                if (parts.Length > 0) FirstName = parts[0];

                if (parts.Length > 1) LastName = parts[1];

            }

        }

    }

}

​

public class Address

{

    public int Id { get; set; }

    public string Street { get; set; }

    public string City { get; set; }

    public string State { get; set; }

    public string PostalCode { get; set; }

    public string Country { get; set; }

}

​