using System;

using System.ComponentModel.DataAnnotations;

using Newtonsoft.Json;

​

class Program

{

    static void Main()

    {

        var example = new 

        {

            DriverMaritalStatus = "INVALID"

        };

        var exampleSerialized = JsonConvert.SerializeObject(example);

        var exampleDeserialized = JsonConvert.DeserializeObject<Example>(exampleSerialized);

        Console.WriteLine(exampleDeserialized.DriverMaritalStatus.ToString());

    }

}

​

public enum DriverMaritalStatus

    {

        NotSpecified,

        NotApplicable,

        Divorced,

        MarriedSameSex,

        Married,

        Single,

        Unknown,

        Widowed,

        Separated

    }

​

public class Example

{

    [EnumDataType(typeof(DriverMaritalStatus))]

    [JsonConverter(typeof(NullableEnumConverter<DriverMaritalStatus>), DriverMaritalStatus.Divorced)]

    public DriverMaritalStatus DriverMaritalStatus { get; set; }    

}

​

public class NullableEnumConverter<T> : JsonConverter<T> where T : struct, Enum

{

    private readonly T _defaultValue;

    public NullableEnumConverter(T defaultValue)

    {

        _defaultValue = defaultValue;

    }

​

    public override T ReadJson(JsonReader reader, Type objectType, T existingValue, bool hasExistingValue, JsonSerializer serializer)

    {

        var enumString = (string)reader.Value;

        if (String.IsNullOrEmpty(enumString))

        {

            return _defaultValue;

        }

​

        try

        {

            return (T)Enum.Parse(typeof(T), enumString, true);

        }

        catch (ArgumentException)

        {

            return _defaultValue;

        }

    }

​

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

    {

        writer.WriteValue(value.ToString());

    }

}