using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

​

public class Program

{

    public static void Main()

    {

        try

        {

            var item = new MyClass();

            item.SomeProperty = "myID";

            item.Items = new List<ChildClass>()

            { 

                new ChildClass() 

                { 

                    cc1IDProperty = "1", 

                    SomeOtherProperty = "2" 

                }, 

                new ChildClass() 

                { 

                    cc1IDProperty = "2", 

                    SomeOtherProperty = "4"

                } 

            };

            item.Items2 = new List<ChildClass2>()

            { 

                new ChildClass2() 

                { 

                    cc2IDProperty = "1", 

                    AnotherProperty = "2" 

                }, 

                new ChildClass2() 

                { 

                    cc2IDProperty = "2", 

                    AnotherProperty = "4"

                } 

            };

            //So I want this call to NOT use the Converter

            JObject messageWithArray = JObject.FromObject(item);

            //I don't know what to put here to attach the DictionaryArrayConverter<ChildClass> to the property "Items"

            var settings = new JsonSerializerSettings() { Converters = new List<JsonConverter>() { new DictionaryArrayConverter<ChildClass>(), new DictionaryArrayConverter<ChildClass2>() }  };

            var serializer = JsonSerializer.CreateDefault(settings);

            //And I want this call to use the Converter.

            var messageWithDictionary = JObject.FromObject(item, serializer);

            Console.WriteLine(messageWithArray);

            Console.WriteLine(messageWithDictionary);

            //And now we test converting them back.

            var arrayMessageToObject = JObject.Parse(messageWithArray.ToString()).ToObject<MyClass>();

            Console.WriteLine("**" + arrayMessageToObject.Items.First().cc1IDProperty + "**");

            var dictMessageToObject = JObject.Parse(messageWithDictionary.ToString()).ToObject<MyClass>(serializer);

            Console.WriteLine("**" + dictMessageToObject.Items.First().cc1IDProperty + "**");

        }

        catch (Exception ex)

        {

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

            Console.WriteLine(ex);

            throw;

        }

    }

}

​

​

public class MyClass

{

    public string SomeProperty { get; set; }

    //This property would enable the dictionary behavior.

    //[JsonConverter(typeof(DictionaryArrayConverter<ChildClass>))]

    public List<ChildClass> Items { get; set; }

    //[JsonConverter(typeof(DictionaryArrayConverter<ChildClass2>))]

    public List<ChildClass2> Items2 { get; set; }

}

​

public class ChildClass

{

    public string cc1IDProperty { get; set; }

    public string SomeOtherProperty { get; set; }

}

​

public class ChildClass2

{

    public string cc2IDProperty { get; set; }

    public string AnotherProperty { get; set; }

}

​

​

class DictionaryArrayConverter<T> : JsonConverter

{

    public override bool CanConvert(Type objectType)

    {

        return typeof(List<T>).IsAssignableFrom(objectType);

    }

​

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

    {

        var jObj = JObject.Load(reader);

​

            var jDict = jObj.ToObject<Dictionary<string, T>>();

            return jDict.Values.ToList();

    }

​

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

    {

        List<T> castObject = (List<T>)value;

        Dictionary<string, T> castDict = new Dictionary<string, T>();

        foreach (dynamic item in castObject)

        {

            if(item is ChildClass)

                castDict.Add(item.cc1IDProperty, item);

            else if(item is ChildClass2)

                castDict.Add(item.cc2IDProperty, item);

        }

​

        serializer.Serialize(writer, castDict);

    }

}

​

​

​