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 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/74624508/custom-json-net-json-converter-with-nested-objects

​

    public class WrapWithValueContractResolver : DefaultContractResolver

    {

        protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)

        {

            var property = base.CreateProperty(member, memberSerialization);

            if (property.Converter == null && property.ItemConverter == null) // property.Converter check is required to avoid applying the converter to WrapWithValueConverter<TValue>.DTO.value

                property.Converter = (JsonConverter)Activator.CreateInstance(typeof(WrapWithValueConverter<>).MakeGenericType(property.PropertyType));

            return property;

        }

    }

    public class WrapWithValueConverter<TValue> : JsonConverter

    {

        // Here we take advantage of the fact that a converter applied to a property has highest precedence to avoid an infinite recursion.

        sealed class DTO { [JsonConverter(typeof(NoConverter)), JsonProperty(ReferenceLoopHandling  = ReferenceLoopHandling.Serialize)] public TValue value { get; set; } public object GetValue() => value; }

​

        public override bool CanConvert(Type objectType) => typeof(TValue).IsAssignableFrom(objectType);

​

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

            => serializer.Serialize(writer, new DTO { value = (TValue)value });

​

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

            => serializer.Deserialize<DTO>(reader)?.GetValue();

    }

​

    public class NoConverter : JsonConverter

    {

        // NoConverter taken from this answer https://stackoverflow.com/a/39739105/3744182

        // By https://stackoverflow.com/users/3744182/dbc

        // To https://stackoverflow.com/questions/39738714/selectively-use-default-json-converter

        public override bool CanConvert(Type objectType)  { throw new NotImplementedException(); /* This converter should only be applied via attributes */ }

        public override bool CanRead => false;

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) => throw new NotImplementedException();

        public override bool CanWrite => false;

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) => throw new NotImplementedException();

    }

​

    public class SalesOrder

    {

        [JsonProperty("project", NullValueHandling = NullValueHandling.Ignore)]

        public int? Project { get; set; }

​

        [JsonProperty("printDescriptionOnInvoice", NullValueHandling = NullValueHandling.Ignore)]

        public bool PrintDescriptionOnInvoice { get; set; }

​

        [JsonProperty("printNoteOnExternalDocuments", NullValueHandling = NullValueHandling.Ignore)]

        public bool PrintNoteOnExternalDocuments { get; set; }

​

        [JsonProperty("printNoteOnInternalDocuments", NullValueHandling = NullValueHandling.Ignore)]

        public bool PrintNoteOnInternalDocuments { get; set; }

​

        [JsonProperty("soBillingContact", NullValueHandling = NullValueHandling.Ignore)]

        public Contact SoBillingContact { get; set; }

    }

​

    public class Contact

    {

        [JsonProperty("overrideContact", NullValueHandling = NullValueHandling.Ignore)]

        public bool OverrideContact { get;set; }

​

        [JsonProperty("attention", NullValueHandling = NullValueHandling.Ignore)]

        public string Attention { get; set; }

​

        [JsonProperty("email", NullValueHandling = NullValueHandling.Ignore)]

        public string Email { get; set; }

​

        [JsonProperty("fax", NullValueHandling = NullValueHandling.Ignore)]

        public string Fax { get; set; }

​

        [JsonProperty("name", NullValueHandling = NullValueHandling.Ignore)]

        public string Name { get; set; }

​

        [JsonProperty("phone1", NullValueHandling = NullValueHandling.Ignore)]

        public string Phone1 { get; set; }

​

        [JsonProperty("phone2", NullValueHandling = NullValueHandling.Ignore)]

        public string Phone2 { get; set; }

​

        [JsonProperty("web", NullValueHandling = NullValueHandling.Ignore)]

        public string Web { get; set; }

    }

​

    class TestClass

    {

        public static void Test()

        {

            DefaultContractResolver resolver = new WrapWithValueContractResolver // Cache statically and reuse for best performance

            {

                //NamingStrategy = new CamelCaseNamingStrategy(), // Uncomment if you need camel case

            }; 

            Test(resolver);

            Test(null);

        }

        static void Test(IContractResolver resolver)

        {

            if (resolver == null)

                Console.WriteLine("\nTesting with no resolver:");

            else

                Console.WriteLine("\nTesting with contract resolver {0}:", resolver);

            var vSalesOrder = new SalesOrder()

            {

                Project = 1,

                PrintDescriptionOnInvoice = true,

                PrintNoteOnExternalDocuments = true,

                SoBillingContact = new Contact

                {

                    Attention = "attention",

                    Email = "@whatever.se",

                    Fax = "lolfax"

                }

            };

            var settings = new JsonSerializerSettings

            {

                ContractResolver = resolver,

            };

            var json = JsonConvert.SerializeObject(vSalesOrder, Formatting.Indented, settings);

            Console.WriteLine(json);

            var order2 = JsonConvert.DeserializeObject<SalesOrder>(json, settings);

            var json2 = JsonConvert.SerializeObject(order2, Formatting.Indented, settings);

            Assert.AreEqual(json, json2);

            Assert.AreEqual(vSalesOrder.Project, order2.Project);

            Assert.AreEqual(vSalesOrder.PrintDescriptionOnInvoice, order2.PrintDescriptionOnInvoice);

            Assert.AreEqual(vSalesOrder.PrintNoteOnExternalDocuments, order2.PrintNoteOnExternalDocuments);

            Assert.AreEqual(vSalesOrder.SoBillingContact.Attention, order2.SoBillingContact.Attention);

            Assert.AreEqual(vSalesOrder.SoBillingContact.Email, order2.SoBillingContact.Email);

            Assert.AreEqual(vSalesOrder.SoBillingContact.Fax, order2.SoBillingContact.Fax);

        }

    }

​

    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;

            }

        }

    }

​