using Newtonsoft.Json;

using System;

​

namespace Rextester

{

    // dummy converter

    public class DecimalJsonConverter : JsonConverter

    {

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

​

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

        {

            throw new NotImplementedException();

        }

​

        public override bool CanConvert(Type objectType)

        {

            return (objectType == typeof(decimal) || objectType == typeof(float) || objectType == typeof(double));

        }

​

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

        {

            var val = JsonConvert.ToString(value);

            writer.WriteRawValue(val);

        }

    }

​

    class DecimalObject

    {

        [JsonConverter(typeof(DecimalJsonConverter))]

        public decimal Bad { get; set; }

        public decimal Good { get; set; }

    }

​

    public class Program

    {

        public static void Main(string[] args)

        {            

            string val = "{ \"Bad\":99999999.99999999, \"Good\":99999999.99999999 }";

            var res = JsonConvert.DeserializeObject<DecimalObject>(val);

            Console.WriteLine("Bad: " + res.Bad + ", Good: " + res.Good);

        }

    }

}