Serializing enums as strings

Enumerations in C# are ints by default, which is fine most of the time. That said, there are situations where you’d want to store and retrieve them using their string names, especially when you are persisting them to a database. The string names make them more readable for one reason. For another, a re-ordering of the enums (caused inadvertently by the addition or removal of an entry) would change their int values, which can potentially break your data when reading them back from a database. Consider the following types – Model and Seasons.

enum Seasons
{
    Spring,
    Summer,
    Fall,
    Winter
}

class Model
{
    public string Name { get; set; } = String.Empty;

    public Seasons Season { get; set; }
}

If you serialize an instance of Model, you’d see the int value for the Season property.

var model = new Model
{
    Name = "Test Model",
    Season = Seasons.Fall,
};

var json  = JsonConvert.SerializeObject(model, Formatting.Indented);
Console.WriteLine(json);

Output looks like this.

{
  "Name": "Test Model",
  "Season": 2
}

It’s fairly easy to change this behavior though. Just add a JsonConverter attribute to the Season property.

class Model
{
    public string Name { get; set; } = String.Empty;

    [JsonConverter(typeof(StringEnumConverter))]
    public Seasons Season { get; set; }
}

Output is now nice and clean.

{
  "Name": "Test Model",
  "Season": "Fall"
}

You get the same behavior both when serializing and deserializing, and the latter is important when reading data back from a database.

How about if you have a collection of enums though? That’s simple too, just replace the JsonConverter attribute with the following JsonProperty attribute.

class Model
{
    public string Name { get; set; } = String.Empty;

    [JsonProperty(ItemConverterType = typeof(StringEnumConverter))]
    public List<Seasons> Seasons { get; set; } = new List<Seasons>();
}

Output is as expected.

{
  "Name": "Test Model",
  "Seasons": [
    "Fall",
    "Winter"
  ]
}

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