Mqtt 连接失败- [反应本机]

Question

我正在尝试连接并从传感器发送的主题中获取数据。 不幸的是，连接不起作用。 在控制台中没有显示没有味精

Ps：我正在使用 react_native_mqtt 库和端口：80

任何帮助表示赞赏。

constructor(){
        super();
        this.onMessageArrived = this.onMessageArrived.bind(this)
        this.onConnectionLost = this.onConnectionLost.bind(this)
        this.onConnect = this.onConnect.bind(this)
        const client = new Paho.MQTT.Client(host, Number(port), clientID);
        client.onMessageArrived = this.onMessageArrived;
        client.onConnectionLost = this.onConnectionLost;
        client.connect({ 
          onSuccess: this.onConnect,
          useSSL: false,
          userName: "user",
          password: "pass",
          onFailure: this.onConnectionLost
    
        });
    
        this.state = {
          message: [''],
          client,
          messageToSend:'',
          isConnected: false,
        };
    
      }
      onConnect = () => {
        const { client } = this.state.client;
        console.log("Connected!!!!");
        client.subscribe(topic, () => {
          console.log('subscribe success topic1');
        });
        this.setState({isConnected: true, error: ''})
      };