using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.Serialization.Formatters;

using System.IO;

using System.Data;

using System.ComponentModel.DataAnnotations;

using System.Globalization;

using System.Reflection;

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

using NUnit.Framework; // Throws NUnit.Framework.AssertionException

​

    public class Portfolio

    {

        public string Name {get; set;}

        public Dictionary<string,Position> Positions {get; set;}

    }

​

    public class Position

    {

        public string Ticker {get; set;}

        public decimal Size {get; set;}

    }

​

    public class PositionDictionaryConverter : DictionaryAsListConverter<Position>

    {

        protected override string GetKey(Position position) { return position.Ticker; }

    }

    public abstract class DictionaryAsListConverter<TValue> : JsonConverter

    {

        protected abstract string GetKey(TValue value);

        public override bool CanConvert(Type objectType)

        {

            return typeof(Dictionary<string, TValue>).IsAssignableFrom(objectType);

        }

​

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

        {

            if (reader.MoveToContent().TokenType == JsonToken.Null)

                return null;

            var list = serializer.Deserialize<List<TValue>>(reader);

            var dictionary = (IDictionary<string, TValue>)(existingValue ?? serializer.ContractResolver.ResolveContract(objectType).DefaultCreator());

            foreach (var item in list)

                dictionary.Add(GetKey(item), item);

            return dictionary;

        }

​

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

        {

            serializer.Serialize(writer, ((IDictionary<string, TValue>)value).Values);

        }

    }

​

    public static partial class JsonExtensions

    {

        public static JsonReader MoveToContent(this JsonReader reader)

        {

            if (reader.TokenType == JsonToken.None)

                reader.Read();

            while (reader.TokenType == JsonToken.Comment && reader.Read())

                ;

            return reader;

        }

    }

​

    class TestClass

    {

        public static void Test()

        {

            var inputJson = GetJson();

            var settings = new JsonSerializerSettings

            {

                Converters = { new PositionDictionaryConverter() },

            };

            var portfolio = JsonConvert.DeserializeObject<Portfolio>(inputJson, settings);

            var json = JsonConvert.SerializeObject(portfolio, Formatting.Indented, settings);

            Console.WriteLine("Deserialized and re-serialized {0}", portfolio);

            Console.WriteLine(json);

            Assert.IsTrue(JToken.DeepEquals(JToken.Parse(json), JToken.Parse(inputJson)));

        }   

        static string GetJson()

        {

            var json = @"{

  ""Name"": ""SP500"",

  ""Positions"": 

  [

      {

        ""Ticker"": ""AOS"",

        ""Size"": 100,

      },

      {

        ""Ticker"": ""ABT"",

        ""Size"": 100,

      }

  ]

}

";

            return json;

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: " + Environment.Version);

            Console.WriteLine("Json.NET version: " + typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​