Json.Net Serialize Dictionary to List

Motivation: Wanted convenience of a Dictionary on the server side MVC controller (for some key look-up based logic), yet send the same list of objects down to Knockout Ajax client, which most readily consumes lists as Javascript object arrays.

Could’ve just exposed the List

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;

namespace YouNameIt {

  using CartItemDict = Dictionary<long, CartItemDto>;

  //reverse of this: https://stackoverflow.com/questions/24759181/deserializing-a-json-dictionaryint-customtype-to-listcustomtype
  //adapted from here: https://james.newtonking.com/json/help/index.html?topic=html/CustomJsonConverter.htm
  public class DictToListConverter : JsonConverter
  {
    public override bool CanConvert(Type objectType)
    {
      return objectType == typeof (Dictionary<object, object>);
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
      throw new NotImplementedException();
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
      var t = JToken.FromObject(value);

      if (t.Type != JTokenType.Object)
      {
        t.WriteTo(writer);
      }
      else
      {
        var o = (JObject) t;
        var values = o.Properties().Select(p => p.Value).ToList();
        (new JArray(values)).WriteTo(writer);
      }
    }
  }

  public class CartDto
  {
    [JsonConverter(typeof(DictToListConverter))]
    public CartItemDict Items { get; set; }

    [DataType(DataType.Currency)]
    public decimal TotalPrice { get; private set; }
  }

  public class CartItemDto : VariantDto
  {
    public long CartItemId { get; private set; }
    public int Quantity { get; private set; }

    [DataType(DataType.Currency)]
    public decimal UnitPrice { get; private set; }
    [DataType(DataType.Currency)]
    public decimal LinePrice { get; private set; }

    private List _addons;
    public List Addons { get { return _addons ?? (_addons = new List()); } }
  }
}