vue3+ts 封装mqtt

在Vue 3和TypeScript中封装MQTT客户端，你可以创建一个可复用的组件或者一个服务。以下是一个简单的封装示例，使用了mqtt包。

首先，安装mqtt包：

npm install mqtt

然后，创建一个封装MQTT的类：

// mqttClient.ts
import mqtt from 'mqtt';
 
export default class MqttClient {
  private client: mqtt.Client;
 
  constructor(private url: string, private options: mqtt.IClientOptions) {
    this.client = mqtt.connect(url, options);
  }
 
  public publish(topic: string, message: string): void {
    this.client.publish(topic, message);
  }
 
  public subscribe(topic: string, callback: mqtt.MessageCallback): void {
    this.client.subscribe(topic, (error, granted) => {
      if (error) {
        console.error(error);
      } else {
        console.log('Subscribed to:', granted);
      }
    });
    this.client.on(topic, callback);
  }
 
  public unsubscribe(topic: string): void {
    this.client.unsubscribe(topic, (error) => {
      if (error) {
        console.error(error);
      } else {
        console.log('Unsubscribed from:', topic);
      }
    });
  }
 
  public end(): void {
    this.client.end();
  }
}

使用该类创建MQTT客户端实例并管理订阅：

// main.ts
import MqttClient from './mqttClient';
 
const url = 'ws://broker.hivemq.com:8000/ws';
const options = {
  clientId: 'myClientId',
  protocolId: 'MQTT',
  protocolVersion: 4,
  clean: true,
  reconnectPeriod: 1000,
  connectTimeout: 30 * 1000,
  will: {
    topic: 'WillTopic',
    payload: 'ConnectionClosedUnexpectedly',
    qos: 0,
    retain: false,
  },
  username: 'yourUsername',
  password: 'yourPassword',
  keepalive: 60,
};
 
const mqttClient = new MqttClient(url, options);
 
mqttClient.subscribe('myTopic', (message) => {
  console.log('Received message on myTopic:', message.toString());
});
 
// 发布消息
mqttClient.publish('myTopic', 'Hello MQTT');
 
// 结束连接
mqttClient.end();

这个简单的封装提供了发布消息、订阅和取消订阅的方法。在实例化MqttClient时，你需要提供MQTT服务器的URL和选项。在订阅回调中，你可以处理接收到的消息。记得在结束使用后调用end()方法来关闭MQTT连接。