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 = @"

            {

              ""Item1"": {

                ""Field1"": ""Val11"",

                ""Field2"": ""Val12""

              },

              ""Item2"": {

                ""Field1"": ""Val21"",

                ""Field2"": ""Val22""

              },

              ""ItemN"": {

                ""Field1"": ""ValN1"",

                ""Field2"": ""ValN2""

              }

            }";

​

        Root root = JsonConvert.DeserializeObject<Root>(json);

        Console.WriteLine("Item 1 Field1: " + root.Item1?.Field1);

        Console.WriteLine("Item 1 Field2: " + root.Item1?.Field2);

        Console.WriteLine();

        Console.WriteLine("Item 2 Field1: " + root.Item2?.Field1);

        Console.WriteLine("Item 2 Field2: " + root.Item2?.Field2);

        Console.WriteLine();

        Console.WriteLine("All Items:");

        foreach (var item in root.Items)

        {

            Console.WriteLine("Field1: " + item?.Field1);

            Console.WriteLine("Field2: " + item?.Field2);

            Console.WriteLine();

        }

    }

}

​

[JsonConverter(typeof(RootConverter))]

public class Root

{

    public Item Item1 { get; set; }

    public Item Item2 { get; set; }

​

    public List<Item> Items; // << all the Items should go here

}

​

public class Item

{

    public string Field1 { get; set; }

    public string Field2 { get; set; }

}

​

public class Foo

{

    public string Bar { get; set; } 

}

​

public class RootConverter : JsonConverter

{

    public override bool CanConvert(Type objectType)

    {

        return objectType == typeof(Root);

    }

​

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

    {

        JObject obj = JObject.Load(reader);

        var root = new Root();

        serializer.Populate(obj.CreateReader(), root);

        root.Items = obj.Properties()

                        .Where(p => p.Value.Type == JTokenType.Object && (p.Value["Field1"] != null || p.Value["Field2"] != null))

                        .Select(p => p.Value.ToObject<Item>())

                        .ToList();

        return root;

    }

​

    public override bool CanWrite

    {

        get { return false; }

    }

​

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

    {

        throw new NotImplementedException();

    }

}

​