Serialize a container of enums as strings using JSON.net

Question

You can serialize an enum field in an WebAPI model as a string by adding an attribute:

enum Size
{
    Small,
    Medium,
    Large
}

class Example1
{
    [Newtonsoft.Json.JsonConverter(typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
    Size Size { get; set; }
}

This will serialize to this JSON:

{
  "Size": "Medium"
}

How can I accomplish the same for a collections of enums?

class Example2
{
    IList<Size> Sizes { get; set; }
}

I want to serialize to this JSON:

{
  "Sizes":
  [
    "Medium",
    "Large"
  ]
}

Answer 1

You need to use JsonPropertyAttribute.ItemConverterType property:

class Example2
{
    [JsonProperty (ItemConverterType = typeof(StringEnumConverter))]
    public IList<Size> Sizes { get; set; }
}

Answer 2

I have this in the startup code of my web app to serialise all enums to strings (I prefer passing enum names to values, makes things more robust).

Must admit I've never tried it on a list of enums though so I don't know what it would do with that - might be worth a try.

var jsonFormatter = config.Formatters.JsonFormatter;
jsonFormatter.SerializerSettings.Converters.Add(new StringEnumConverter { CamelCaseText = true });