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/69543853/user-defined-struct-and-deserialization

​

    [JsonConverter(typeof(PriceConverter))]

    public struct Price

    {

        private readonly decimal _value;

​

        public Price(Price value)

        {

            _value = value._value;

        }

​

        public Price(decimal value)

        {

            _value = value;

        }

​

        public static implicit operator decimal(Price p)

        {

            return p._value;

        }

​

        public static implicit operator Price(decimal d)

        {

            return new Price(d);

        }

    }

​

    class PriceConverter : JsonConverter<Price>

    {

        public override Price ReadJson(JsonReader reader, Type objectType, Price existingValue, bool hasExistingValue, JsonSerializer serializer) =>

            reader.ValueType == typeof(double) ? throw new JsonSerializationException("Double value for Price") : serializer.Deserialize<decimal>(reader);

​

        public override void WriteJson(JsonWriter writer, Price value, JsonSerializer serializer) =>

            serializer.Serialize(writer, (decimal)value);

    }

​

    public class FloatParseHandlingConverter : JsonConverter

    {

        readonly FloatParseHandling floatParseHandling;

​

        public FloatParseHandlingConverter(FloatParseHandling floatParseHandling)

        {

            this.floatParseHandling = floatParseHandling;

        }

​

        public override bool CanConvert(Type objectType)

        {

            throw new NotImplementedException();

        }

​

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

        {

            if (reader.TokenType == JsonToken.Null)

                return null;

            var old = reader.FloatParseHandling;

            try

            {

                reader.FloatParseHandling = floatParseHandling;

                existingValue = existingValue ?? serializer.ContractResolver.ResolveContract(objectType).DefaultCreator();

                serializer.Populate(reader, existingValue);

                return existingValue;

            }

            finally

            {

                reader.FloatParseHandling = old;

            }

        }

​

        public override bool CanWrite { get { return false; } }

​

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

        {

            throw new NotImplementedException();

        }

    }

​

    [JsonConverter(typeof(FloatParseHandlingConverter), FloatParseHandling.Decimal)]

    public class Product

    {

        public string Name { get; set; }

        public Price Price { get; set; }

    }

​

    class TestClass

    {

        public static void Test()

        {

            Product product1 = new Product();

            product1.Name = "Hans";

            product1.Price = 2.30m;

​

            string priceSer = JsonConvert.SerializeObject(product1);

            Product product2 = JsonConvert.DeserializeObject<Product>(priceSer);

            Console.WriteLine(priceSer);

            Console.WriteLine("Initial price: {0}", (decimal)product1.Price);

            Console.WriteLine("Round-tripped price: {0}", (decimal)product2.Price);

            var json2 = JsonConvert.SerializeObject(product2);

            Assert.AreEqual(priceSer, json2, $"Original and round-tripped {product1} serialized to JSON differ.");

​

            Assert.AreEqual(((decimal)product1.Price).ToString(NumberFormatInfo.InvariantInfo), ((decimal)product2.Price).ToString(NumberFormatInfo.InvariantInfo), "Original and round-tripped price differ.");

        }   

    }

​

    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.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;

        }

    }

​