onMessage.dart

onMessage.dart

void _onMessage(List<mqtt.MqttReceivedMessage> event) {
 final mqtt.MqttPublishMessage recMess =
 event[0].payload as mqtt.MqttPublishMessage;
 final String message =
 mqtt.MqttPublishPayload.bytesToStringAsString(recMess.payload.message);

 setState(() {
   _temp = double.parse(message);
 });
}