using Newtonsoft.Json.Converters;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json.Serialization;
public static void Main()
JsonConvert.DefaultSettings = () => new JsonSerializerSettings
ContractResolver = new CamelCasePropertyNamesContractResolver()
var json1 = "{\"discriminator\":\"typeA\",\"value\":{\"propA\":\"sample data A\"}}";
var json2 = "{\"discriminator\":\"typeB\",\"value\":{\"propB\":\"sample data B\"}}";
Console.WriteLine("json 1: " + json1);
Console.WriteLine("json 2: " + json2);
DiscriminatedUnion discUnion1 = JsonConvert.DeserializeObject<DiscriminatedUnion>(json1);
DiscriminatedUnion discUnion2 = JsonConvert.DeserializeObject<DiscriminatedUnion>(json2);
Console.WriteLine("json 1 type: " + discUnion1.Value.GetType().Name);
Console.WriteLine("json 1 propA: " + ((TypeA) discUnion1.Value).PropA);
Console.WriteLine("json 2 type: " + discUnion2.Value.GetType().Name);
Console.WriteLine("json 2 propB: " + ((TypeB) discUnion2.Value).PropB);
Console.WriteLine("Reserialized json 1: " + JsonConvert.SerializeObject(discUnion1));
Console.WriteLine("Reserialized json 2: " + JsonConvert.SerializeObject(discUnion2));
[JsonConverter(typeof(UnionConverter))]
public class DiscriminatedUnion {
public DiscriminatorType Discriminator {get; set;}
public object Value {get; set;}
[JsonConverter(typeof(CamelCaseStringEnumConverter))]
public enum DiscriminatorType {
public string PropA {get; set;}
public string PropB {get; set;}
public class CamelCaseStringEnumConverter : StringEnumConverter {
public CamelCaseStringEnumConverter(): base() {
public class UnionConverter : JsonConverter
public override bool CanConvert(Type objectType)
return objectType == typeof(DiscriminatedUnion);
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) {
throw new NotSupportedException("can't write");
public override bool CanWrite
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
var discUnion = new DiscriminatedUnion();
serializer.Populate(reader, discUnion);
var jObject = (JObject) discUnion.Value;
switch(discUnion.Discriminator)
case DiscriminatorType.TypeA:
discUnion.Value = jObject.ToObject<TypeA>();
case DiscriminatorType.TypeB:
discUnion.Value = jObject.ToObject<TypeB>();