Custom Json Serialization for ASP.NET MVC

JsonDotNetValueProviderFactory.cs

/// <summary>
/// From https://github.com/garysharp/Disco/commit/1dfa3f4f15fe4fc093e90e4cd490dd06cc30cf07
/// </summary>
public class JsonDotNetValueProviderFactory : ValueProviderFactory
{
    private readonly JsonSerializerSettings serializerSettings;

    public JsonDotNetValueProviderFactory(JsonSerializerSettings serializerSettings)
    {
        Guard.Against.Null(serializerSettings, nameof(serializerSettings));

        this.serializerSettings = serializerSettings;
    }

    public override IValueProvider GetValueProvider(ControllerContext controllerContext)
    {
        Guard.Against.Null(controllerContext, nameof(controllerContext));

        var request = controllerContext.HttpContext.Request;

        if (!request.ContentType.StartsWith("application/json", StringComparison.OrdinalIgnoreCase))
        {
            return null;
        }

        if (request.InputStream.Length == 0)
        {
            return null;
        }

        var jsonSerializer = JsonSerializer.Create(serializerSettings);

        jsonSerializer.Converters.Add(new ExpandoObjectConverter());

        using (var streamReader = new StreamReader(request.InputStream, Encoding.UTF8, true, 0x400, true))
        {
            using (var jsonReader = new JsonTextReader(streamReader))
            {
                var bodyObject = jsonSerializer.Deserialize<ExpandoObject>(jsonReader);

                return new DictionaryValueProvider<object>(bodyObject, CultureInfo.CurrentCulture);
            }
        }
    }
}