using System;

using Newtonsoft.Json;

​

​

​

public class ValueToStringConverter : JsonConverter

{

    public override bool CanRead => false;

    public override bool CanConvert(Type objectType) => objectType.IsValueType;

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

        => throw new NotSupportedException();

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

    {

        var str = value?.ToString();

        writer.WriteValue(str);

    }

}

​

​

public class Model

{

    [JsonConverter(typeof(ValueToStringConverter))]

    public int IntValue {get; set;}

​

    [JsonConverter(typeof(ValueToStringConverter))]

    public Decimal DecimalValue {get; set;}

}

​

​

​

public class Program

{

    public static void Main()

    {

        var m = new Model()

        {

            IntValue = 42,

            DecimalValue = 3.1415926535897932384626433m

        };

        Console.WriteLine($"m.IntValue = {m.IntValue}");

        Console.WriteLine($"m.DecimalValue = {m.DecimalValue}");

        Console.WriteLine("----------------------------------------");

        var json = JsonConvert.SerializeObject(m);

        Console.WriteLine(json);

        Console.WriteLine("----------------------------------------");

        var deserializationResult = JsonConvert.DeserializeObject<Model>(json);

        Console.WriteLine($"m.IntValue == deserializationResultIntValue : {m.IntValue == deserializationResult.IntValue}");

        Console.WriteLine($"m.DecimalValue == deserializationResult.DecimalValue : {m.DecimalValue == deserializationResult.DecimalValue}");

    }

}