using System;

using System.Globalization;

using Newtonsoft.Json;

using Newtonsoft.Json.Serialization;

​

public class Program

{

    public static void Main()

    {

        PosInvoice inv = new PosInvoice

        {

            Description = "Services",

            UnitPrice = 90.0m,

            Quantity = 2.0m,

            TotalAmount = 180.0m,

        };

​

        Console.WriteLine(SerializeInvoice(inv, true));   // endpoint 1

        Console.WriteLine();

        Console.WriteLine(SerializeInvoice(inv, false));  // endpoint 2

    }

    static string SerializeInvoice(PosInvoice invoice, bool serializeDecimalsAsStrings)

    {

        var settings = new JsonSerializerSettings { Formatting = Formatting.Indented };

        if (serializeDecimalsAsStrings)

        {

            settings.Converters.Add(new InvoiceAmountsAsStringsConverter());

        }

        return JsonConvert.SerializeObject(invoice, settings);

    }

}

​

public class PosInvoice

{

    public string Description { get; set; }

    public decimal UnitPrice { get; set; }

    public decimal Quantity { get; set; }

    public decimal TotalAmount { get; set; }

}

​

public class InvoiceAmountsAsStringsConverter : JsonConverter

{

    public override bool CanConvert(Type objectType)

    {

        return objectType == typeof(PosInvoice);

    }

​

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

    {

        PosInvoice invoice = (PosInvoice)value;

        JsonObjectContract contract = (JsonObjectContract)serializer.ContractResolver.ResolveContract(typeof(PosInvoice));

        writer.WriteStartObject();

        foreach (JsonProperty prop in contract.Properties)

        {

            writer.WritePropertyName(prop.PropertyName);

            object propValue = prop.ValueProvider.GetValue(invoice);

            if (propValue is decimal)

            {

                writer.WriteValue(((decimal)propValue).ToString(CultureInfo.InvariantCulture));

            }

            else

            {

                serializer.Serialize(writer, propValue);

            }

        }

        writer.WriteEndObject();

    }

​

    public override bool CanRead

    {

        get { return false; }

    }

​

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

    {

        throw new NotImplementedException();

    }

}

​