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/54341115/jobject-tostring-with-stringenumconverter-not-working

​

    public enum ErrorCode 

    {

        A,

        B,

        C

    }

​

    class TestClass

    {

        public static void Test()

        {

            var response = JObject.FromObject(

                new

                {

                    Error = new

                    {

                        Message = "Test",

                        Code = ErrorCode.A

                    }

                },

                JsonSerializer.CreateDefault(new JsonSerializerSettings { Converters = { new StringEnumConverter() } })

            )

            .ToString(Formatting.None);

            Console.WriteLine(response);

            // Now try serializing to JObject without StringEnumConverter.  Note that the value of 

            // Error.Code will be of type System.Int32

            var obj = JObject.FromObject(

                new

                {

                    Error = new

                    {

                        Message = "Test",

                        Code = ErrorCode.A

                    }

                },

                JsonSerializer.CreateDefault(new JsonSerializerSettings {  })

            );  

            Console.WriteLine(obj.SelectToken("Error.Code"));

            Console.WriteLine(((JValue)obj.SelectToken("Error.Code")).Value.GetType());

            // Here's an example of using a JsonConverter that applies to primitives with ToString()

            var convertedJson = obj.ToString(Formatting.None, new PrefixingStringConverter("converter prefix:   "));

            Console.WriteLine(convertedJson);

        }

        static string GetJson()

        {

            var json = @"

";

            return json;

        }

    }

​

    public class PrefixingStringConverter : JsonConverter

    {

        // Taken from this answer https://stackoverflow.com/a/46797460/3744182

        // To https://stackoverflow.com/questions/46788778/how-to-deserialize-dodgy-json-with-improperly-quoted-strings-and-missing-brack

        readonly string prefix;

        public PrefixingStringConverter(string prefix)

        {

            this.prefix = prefix;

        }

​

        public override bool CanConvert(Type objectType)

        {

            return objectType == typeof(string);

        }

​

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

​

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

        {

            throw new NotImplementedException();

        }

​

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

        {

            var s = (string)value;

            writer.WriteValue(prefix + s);

        }

    }

​

    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;

            }

        }

    }

​