using System;

using Newtonsoft.Json;

using Newtonsoft.Json.Serialization;

using System.Collections.Generic;

using JsonSubTypes;

​

public class Program

{

    public static void Main()

    {

        JsonConvert.DefaultSettings = () => {

            return new JsonSerializerSettings() {

                ContractResolver = new DefaultContractResolver() {

                    NamingStrategy = new SnakeCaseNamingStrategy()

                },

                Converters = new List<JsonConverter>() {

                    JsonSubtypesConverterBuilder.Of(typeof(ItemBase), "type")

                        .RegisterSubtype(typeof(ItemDerived1), "A")

                        .RegisterSubtype(typeof(ItemDerived2), "B")

                        .RegisterSubtype(typeof(SubItems), "sub")

                        .Build()

                }

            };

        };

        var json = @"{

    ""containers"": [

        {

            ""name"": ""container1"",

            ""items"": [

                {

                    ""type"": ""A"",

                    ""base_prop_str"": ""example1"",

                    ""base_prop_int"": 45,

                    ""prop_deriv_a"": ""derived1""

                },

                {

                    ""type"": ""B"",

                    ""base_prop_str"": ""example2"",

                    ""base_prop_int"": 34,

                    ""prop_deriv_b"": 8857

                },

                {

                    ""type"": ""sub"",

                    ""base_prop_str"": ""example3"",

                    ""base_prop_int"": 567,

                    ""items"": [

                        {

                            ""type"": ""A"",

                            ""base_prop_str"": ""example4""

                        }

                    ]

                }

            ]

        }

    ]

}";

        Container c = null;

        try {

            c = JsonConvert.DeserializeObject<Container>(json);

        }

        catch (Exception e) {

            Console.WriteLine($"Error while deserializing: {e.Message}");

        }

        if (c == null) {

            Console.WriteLine("container is null");

            return;

        }

        if (c.Containers == null) {

            Console.WriteLine("containers is null");

            return;

        }

        foreach (var container in c.Containers) {

            Console.WriteLine("container name: " + container.Name);

            Console.WriteLine("items count: " + container.Items.Count.ToString());

            Console.WriteLine();

            foreach (var item in container.Items) {

                if (item == null) {

                    Console.WriteLine("item is null");

                    Console.WriteLine();

                    continue;

                }

                Console.WriteLine("item C# type: " + item.GetType().Name);

                Console.WriteLine("item type: " + item.Type);

                Console.WriteLine("item base str: " + item.BasePropStr);

                Console.WriteLine("item base int: " + item.BasePropInt.ToString());

                if (item is ItemDerived1 derivA) {

                    Console.WriteLine("derived A prop: " + derivA.PropDerivA);

                }

                if (item is ItemDerived2 derivB) {

                    Console.WriteLine("derived B prop: " + derivB.PropDerivB);

                }

                if (item is SubItems subs) {

                    Console.WriteLine("subitem count: " + subs.Items.Count);

                }

                Console.WriteLine();

            }

            Console.WriteLine();

        }

    }

}

​

public abstract class ItemBase {

    public string Type { get; set; }

    public string BasePropStr { get; set; }

    public int BasePropInt { get; set; }

}

​

public class ItemDerived1 : ItemBase {

    public string PropDerivA { get; set; }

}

​

public class ItemDerived2 : ItemBase {

    public int PropDerivB { get; set; }

}

​

public class SubItems : ItemBase {

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

}

​

public class SubContainer {

    public string Name { get; set; }

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

}

​

public class Context {

    public List<SubContainer> GetItems() {

        return _items;

    }

    public void AddSubContainer(SubContainer item) {

        _items.Add(item);

    }

    private List<SubContainer> _items = new List<SubContainer>();

}

​

public class Container {

    public List<SubContainer> Containers {

        get {

            return _context?.GetItems();

        }

        set {

            foreach (var item in value) {

                _context.AddSubContainer(item);

            }

        }}

    private Context _context = new Context();

}

​