I have an interface like so

public interface INetworkPacketEventHandler
{
    int Id { get; }
    Task HandleAsync(INetworkClient client, INetworkPacketReader reader);
}

I want to get a Dictionary<short, Type> so I can later know which handler to create from the identifier.

I have this, but it always returns an empty IEnumerable

var types =
            from type in Assembly.GetExecutingAssembly().GetTypes()
            where type.IsDefined(typeof(INetworkPacketEventHandler), true)
            select new KeyValuePair<short, Type>((short)type.GetProperty("Id").GetValue(type), type);