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 System.Runtime.Serialization;

​

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

​

using Utf8Json;

using Utf8Json.Resolvers;

​

//https://stackoverflow.com/questions/65140592/utf8json-type-is-not-registered-in-this-resolverenumunderlyingvalueresolver

​

    [DataContract]

    public class Physics

    {

        [DataMember]

        public string Lecturer { get; set; }

​

        [DataMember]

        public WeekDays WeekDay { get; set; }

    }

​

    [DataContract]

    public enum WeekDays : byte

    {

        [EnumMember]

        Monday = 1,

​

        [EnumMember]

        Tuesday,

​

        [EnumMember]

        Wednesday,

​

        [EnumMember]

        Thursday,

​

        [EnumMember]

        Friday,

​

        [EnumMember]

        Saturday,

​

        [EnumMember]

        Sunday

    }

​

    public static class Utf8JsonConfiguration

    {

        static public IJsonFormatterResolver Resolver { get; } = 

            CompositeResolver.Create(EnumResolver.UnderlyingValue, StandardResolver.Default);

    }

​

    class TestClass

    {

        public static void Test()

        {

            var physics_1 = new Physics { Lecturer = "Andrew", WeekDay = WeekDays.Monday };

            var v1 = JsonSerializer.Serialize(physics_1, Utf8JsonConfiguration.Resolver);

            Console.WriteLine(Encoding.UTF8.GetString(v1));

            var physics_2 = JsonSerializer.Deserialize<Physics>(v1, Utf8JsonConfiguration.Resolver);

            Assert.AreEqual(physics_1.Lecturer, physics_2.Lecturer);

            Assert.AreEqual(physics_1.WeekDay, physics_2.WeekDay);

        }   

    }

​

    public class Program

    {

        public static void Main()

        {

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

            Console.WriteLine("System.Text.Json version: " + 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.Location.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;

        }

    }

​