json-serialization-4.cs

public class MyApiControllerAttribute : ActionFilterAttribute
{
    public override void OnActionExecuted(ActionExecutedContext ctx)
    {
        if (ctx.Result is ObjectResult objectResult)
        {
            var settings = new JsonSerializerSettings
            {
                NullValueHandling = NullValueHandling.Ignore,
                ContractResolver = new MyApiContractResolver(),
            };
            settings.Converters.Add(new StringEnumConverter());
            objectResult.Formatters.Add(new NewtonsoftJsonOutputFormatter(
                settings,
                ctx.HttpContext.RequestServices.GetRequiredService<ArrayPool<char>>(),
                ctx.HttpContext.RequestServices.GetRequiredService<IOptions<MvcOptions>>().Value,
                new MvcNewtonsoftJsonOptions()));
        }
    }
}

internal class MyApiContractResolver : DefaultContractResolver
{
    public MyApiContractResolver() =>
        NamingStrategy = new CamelCaseNamingStrategy
        {
            ProcessDictionaryKeys = true,
        };

    protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
    {
        IList<JsonProperty> properties = base.CreateProperties(type, memberSerialization);
        return properties
            .OrderBy(p => p.Order ?? int.MaxValue)
            .ThenBy(p => p.PropertyName)
            .ToList();
    }
}