private static void OnConnected(object param, MqttClientConnectedEventArgs args) { Console.WriteLine("### CLIENT CONNECTING ###"); SystemEvent systemEvent = new SystemEvent(SystemEventTypesEnum.DeviceOnline, null, null, args.ClientId); var jsonMessage = JsonConvert.SerializeObject(systemEvent, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore }); producer.ProduceMessage(Literals.KAFKA_TOPIC_DEVICESTATUS, jsonMessage); Console.WriteLine("### CLIENT CONNECTED ###"); }