using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

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

​

//https://stackoverflow.com/questions/78353143/custom-jsonconverter-for-seserializing-json-to-abstract-class

​

public class Events

{

    public int id;

    public ActionsHolder[] actions;

}

​

[JsonConverter(typeof(BaseConverter))]

public class ActionsHolder

{

    public int id { get; set; } = -1;

    public ActionBase values { get; set; }

}

​

public abstract class ActionBase : ActionsHolder

{

    public int obj_id { get; set; }

}

​

public class OpenURLAction : ActionBase

{

    //Action id 8 = Open URL

    public string url { get; set; }

}

​

public class ScaleAction : ActionBase

{

    //Action id 15 = Scale

    public float scale { get; set; } = 1;

}

​

public class BaseConverter : JsonConverter

{

    static JsonSerializerSettings SpecifiedSubclassConversion = new JsonSerializerSettings() 

    { 

        ContractResolver = new BaseSpecifiedConcreteClassConverter() ,

        TypeNameHandling = TypeNameHandling.All

    };

​

    public override bool CanConvert(Type objectType)

    {

        return (objectType == typeof(ActionsHolder));

    }

​

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

    {

        JObject joAction = JObject.Load(reader);

​

        JObject joValues = (JObject)joAction["values"];

        switch (joAction["id"].Value<int>())

        {

            case 8:

                return new ActionsHolder

                {

                    id = joAction["id"].Value<int>(),

                    values = JsonConvert.DeserializeObject<OpenURLAction>(joValues.ToString(), SpecifiedSubclassConversion)

                };

            case 15:

                return new ActionsHolder

                {

                    id = joAction["id"].Value<int>(),

                    values = JsonConvert.DeserializeObject<ScaleAction>(joValues.ToString(), SpecifiedSubclassConversion)

                };

            default:

                return null;

        }

        throw new NotImplementedException();

    }

​

    public override bool CanWrite

    {

        get { return false; }

    }

​

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

    {

        throw new NotImplementedException();

        // returns false; // Fixed compilation

    }

}

​

    class TestClass

    {

        public static void Test()

        {

        }   

        static string GetJson() =>@"

";

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1}), {2}", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , Environment.Version, Environment.OSVersion);

            Console.WriteLine("{0} version: {1}", typeof(JsonSerializer).Namespace, typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

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

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​