Deserialize json based on fields in .Net (C#)

Question

I\'m writing an app that gets a Json list of objects like this:

[
   {
       \"ObjectType\": \"apple\",
       \"ObjectSize\": 35,
       \"ObjectC         


        

Answer 1

Some time ago I had the same problem.

You'll can use Json.NET, but if you don't have control over the json document (as in: 'it has been serialized by some other framework') you'll need to create a custom JsonConverter like this:

class MyItemConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return typeof(ItemToSell).IsAssignableFrom(objectType);
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        JObject obj = JObject.Load(reader);
        string discriminator = (string)obj["ObjectType"];

        ItemToSell item;
        switch (discriminator)
        {
            case "apple":
                item = new Apple();
                break;
            case "books":
                item = new Books();
                break;
            case "melon":
                item = new Melon();
                break;
            default:
                throw new NotImplementedException();
        }

        serializer.Populate(obj.CreateReader(), item);

        return item;

    }


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

    }
}

Then you'll need to add it to the converters of the JsonSerializerSettings like so:

JsonSerializerSettings settings = new JsonSerializerSettings
{
    TypeNameHandling = TypeNameHandling.Objects,

};
settings.Converters.Add(new MyItemConverter());
var items = JsonConvert.DeserializeObject>(response, settings);