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/53736394/convert-c-sharp-class-to-json-with-customized-structure

    public class NestedValueConverter<T> : JsonConverter

    {

        class Value

        {

            public T value { get; set; }

        }

​

        public override bool CanConvert(Type objectType)

        {

            throw new NotImplementedException();

        }

​

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

        {

            switch (reader.MoveToContent().TokenType)

            {

                case JsonToken.Null:

                    return null;

​

                default:

                    return serializer.Deserialize<Value>(reader).value;

            }

        }

​

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

        {

            serializer.Serialize(writer, new Value { value = (T)value });

        }

    }

​

    public static partial class JsonExtensions

    {

        public static JsonReader MoveToContent(this JsonReader reader)

        {

            if (reader.TokenType == JsonToken.None)

                reader.Read();

            while (reader.TokenType == JsonToken.Comment && reader.Read())

                ;

            return reader;

        }

    }

​

    public class PrimaryContact

    {

        [JsonConverter(typeof(NestedValueConverter<string>))]

        public string PrefixTitle { get; set; }

​

        public string SurName { get; set; }

​

        public string GivenName { get; set; }

    }

​

    public class RootObject

    {

        public PrimaryContact PrimaryContact { get; set; }

    }

​

    class TestClass

    {

        public static void Test()

        {

            var jsonString = GetJson();

            var settings = new JsonSerializerSettings

            {

                ContractResolver = new CamelCasePropertyNamesContractResolver(),

            };

            var root = JsonConvert.DeserializeObject<RootObject>(jsonString, settings);

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

            Console.WriteLine(json2);

​

            Assert.IsTrue(JToken.DeepEquals(JToken.Parse(jsonString), JToken.Parse(json2)));

​

            Assert.IsTrue(root.PrimaryContact.PrefixTitle == "mrs");

        }   

        static string GetJson()

        {

            var json = @"{

""primaryContact"": {

      ""prefixTitle"": {

        ""value"": ""mrs""

      },

      ""surName"": ""abcd"",

      ""givenName"": ""abcd""      

    }

}

";

            return json;

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: " + Environment.Version);

            Console.WriteLine("Json.NET version: " + typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

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

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​