AutoPropertyAndFieldResolver.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Runtime.CompilerServices;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;

namespace MyNamespace
{
    public class AutoPropertyAndFieldResolver : DefaultContractResolver
    {
        protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
        {
            var jsonProperty = base.CreateProperty(member, memberSerialization);
            var fieldInfo = member as FieldInfo;
            if (fieldInfo != null)
            {
//                if (fieldInfo.IsInitOnly)
                {
                    jsonProperty.Writable = true;
                }
                jsonProperty.Readable = true;
            }
            
            var property = member as PropertyInfo;
            if (property != null)
            {
                jsonProperty.Ignored = !IsAutoInstanceProperty(property);
            }
            return jsonProperty;
        }

        private static bool IsAutoInstanceProperty(PropertyInfo property)
        {
            if (property.GetGetMethod() != null && !property.GetGetMethod().HasAttribute<CompilerGeneratedAttribute>())
            {
                return false;
            }
            Debug.Assert(property.DeclaringType != null, "property.DeclaringType != null");
            var relativeFields = property.DeclaringType.GetFields(BindingFlags.NonPublic | BindingFlags.Instance);
            return relativeFields.Any(f => f.Name.Contains(property.Name) && f.Name.Contains("BackingField") && f.HasAttribute<CompilerGeneratedAttribute>());
        }

        protected override List<MemberInfo> GetSerializableMembers(Type objectType)
        {
            var members = objectType.GetProperties(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)
                .Cast<MemberInfo>()
                .Union(objectType.GetAllInstanceFields().Where(f => !f.HasAttribute<CompilerGeneratedAttribute>()))
                .ToList();
            return members;
        }
    }

    public static class MemberInfoExtension
    {
        public static bool HasAttribute<T>(this MemberInfo memberInfo)
        {
            return memberInfo.GetCustomAttributes(typeof(T), true).Any();
        }

        public static IEnumerable<FieldInfo> GetAllInstanceFields(this Type t)
        {
            if (t == null)
                return Enumerable.Empty<FieldInfo>();

            var flags = BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.DeclaredOnly;
            return t.GetFields(flags).Concat(GetAllInstanceFields(t.BaseType));
        }
    }
}