using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.Serialization.Formatters;

using System.IO;

using System.Data;

using System.ComponentModel.DataAnnotations;

using System.Globalization;

using System.Reflection;

using System.Collections.ObjectModel;

​

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/61204905/c-json-typenamehandling-only-when-serializationbinder-is-triggered

​

    public class CharacterData { }

​

    public class Rage { }

​

    public class Mana { }

​

    public class DoNotShowMyTypeName { }

​

    public class CharacterDataSerializationBinder : ISerializationBinder

    {

        readonly ISerializationBinder defaultBinder;

​

        public CharacterDataSerializationBinder() : this(null) { }

        public CharacterDataSerializationBinder(ISerializationBinder defaultBinder) { this.defaultBinder = defaultBinder; }

        void ISerializationBinder.BindToName(Type serializedType, out string assemblyName, out string typeName)

        {

            switch (serializedType.Name)

            {

                case "CharacterData":

                    assemblyName = "CharacterData";

                    typeName = serializedType.Name;

                    break;                

                case "Rage":

                    assemblyName = "Rage";

                    typeName = serializedType.Name;

                    break;                

                case "Mana":

                    assemblyName = "Mana";

                    typeName = serializedType.Name;

                    break;

                default:

                    if (defaultBinder == null)

                        assemblyName = typeName = null;

                    else

                        defaultBinder.BindToName(serializedType, out assemblyName, out typeName);

                    break;

            }

        }

​

        Type ISerializationBinder.BindToType(string assemblyName, string typeName)

        {

            switch (assemblyName)

            {

                case "CharacterData":

                    return typeof(CharacterData);                

                case "Rage":

                    return typeof(Rage);                

                case "Mana":

                    return typeof(Mana);

                default:

                    if (defaultBinder == null)

                        return null;

                    return defaultBinder.BindToType(assemblyName, typeName);

            }

        }

    }

​

    class TestClass

    {

        public static void Test()

        {

            Test(new DefaultSerializationBinder());

            Test(null);

        }   

        public static void Test(ISerializationBinder innerBinder)

        {

            Console.WriteLine("\nTesting innerBinder {0}:", innerBinder == null ? "null" : innerBinder.ToString());

            var test = new List<object>

            {

                new CharacterData(),

                new Mana(),

                new Rage(),

                new DoNotShowMyTypeName(),

                new Dictionary<string, object>

                {

                    { "one", new CharacterData() },

                    { "two", new DoNotShowMyTypeName() },

                },

                new object [] { "hello", new CharacterData(), new DoNotShowMyTypeName() },

            };

            var settings = new JsonSerializerSettings

            {

                TypeNameHandling = TypeNameHandling.Auto,

                SerializationBinder = new CharacterDataSerializationBinder(innerBinder)

            };

            var jsonData = JsonConvert.SerializeObject(test, Formatting.Indented, settings);

            Console.WriteLine(jsonData);

        }   

    }

​

    public class Program

    {

        public static void Main()

        {

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

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

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

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

                Console.WriteLine(ex);

                throw;

            }

        }

        public static string GetNetCoreVersion()

        {

            //https://techblog.dorogin.com/how-to-detect-net-core-version-in-runtime-ecd65ad695be

            //

            var assembly = typeof(System.Runtime.GCSettings).GetTypeInfo().Assembly;

            var assemblyPath = assembly.CodeBase.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);

            int netCoreAppIndex = Array.IndexOf(assemblyPath, "Microsoft.NETCore.App");

            if (netCoreAppIndex > 0 && netCoreAppIndex < assemblyPath.Length - 2)

                return assemblyPath[netCoreAppIndex + 1];

            return null;

        }

    }

​