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/29572022/override-global-json-net-enum-handling-for-one-particular-enum-via-decoration/29592249?noredirect=1#comment109194891_29592249

​

public class ForceNumericFlagEnumConverter : JsonConverter

{

    public override bool CanConvert(Type objectType)

    {

        if (!(Nullable.GetUnderlyingType(objectType) ?? objectType).IsEnum)

            return false;

        return HasFlagsAttribute(objectType);

    }

​

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

​

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

​

    static bool HasFlagsAttribute(Type objectType) 

    { 

        return Attribute.IsDefined(Nullable.GetUnderlyingType(objectType) ?? objectType, typeof(System.FlagsAttribute));

    }

​

    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)

    {

        throw new NotImplementedException();

    }

}

​

public class Program

{

    public static void Main()

    {

        try

        {

            Test(UserCan.ChangeConf | UserCan.ForceOther);

            Test(UserCan.DoNothing);

            Test(UserCan.ForceOther);

            Test(UserCan.DoEverything);

        }

        catch (Exception ex)

        {

            Console.WriteLine("Uncaught exception:");

            Console.WriteLine(ex);

            throw;

        }

    }

​

    static void Test(UserCan ability)

    {

        JsonConvert.DefaultSettings = () => GetGlobalJsonSettings();

        var settings = GetNEWJsonSettings();

        string jsonAbility = JsonConvert.SerializeObject(ability, settings);

        Console.WriteLine("\nJSON serialization for {0} \"{1}\":", ability.GetType(), ability);

        Console.WriteLine(jsonAbility);

        long val;

        Assert.IsTrue(long.TryParse(jsonAbility, out val));

        var result1 = JsonConvert.DeserializeObject<UserCan?>(jsonAbility, settings);

        var result2 = JsonConvert.DeserializeObject<UserCan>(jsonAbility, settings);

        Assert.IsTrue(result1 == ability);

        Assert.IsTrue(result2 == ability);

        Assert.AreEqual("\"someValue\"", JsonConvert.SerializeObject(NonFlagEnum.SomeValue, settings));

    }

    public enum NonFlagEnum

    {

        SomeValue,

    }

    [Flags]

    public enum UserCan : long

    {

        DoNothing = 0,

        ChangeConf =               1 << 0,

        MonitorOthers =              1 << 1,

        ForceOther =                1 << 2,

        EditRemoveOthers =           1 << 3,

        DoEverything = long.MaxValue,

    }

    public static JsonSerializerSettings GetGlobalJsonSettings()

    {       

        JsonSerializerSettings settings = new JsonSerializerSettings

        {

            Converters = { new StringEnumConverter{ CamelCaseText = true } },

        };

        return settings;

    }

    public static JsonSerializerSettings GetNEWJsonSettings()

    {

        JsonSerializerSettings settings = new JsonSerializerSettings

        {

            DefaultValueHandling = DefaultValueHandling.IgnoreAndPopulate,

            NullValueHandling = NullValueHandling.Ignore,

            ObjectCreationHandling = ObjectCreationHandling.Replace, 

            TypeNameHandling = TypeNameHandling.Auto,

            Converters = { new ForceNumericFlagEnumConverter() },

        };

        return settings;

    }

}

​

​