vue 连接mqtt

const mqttConfig = {  
  // 你的 MQTT 服务器配置  
  protocolId: 'MQTT',
  protocolVersion: 4,
  clean: true,
  clientId: 'xxxx',
  reconnectPeriod: 1000,
  connectTimeout: 60 * 1000,
  // will: {
  //   topic: 'WillTopic',
  //   payload: 'Connection Closed Unexpectedly!',
  //   qos: 0,
  //   retain: false
  // },
  username: 'xxxx', // 如果需要
  password: 'xxxxx', // 如果需要
  // 其他配置...  
};  
export function useMqtt() {
  const client = ref(null);
  const listeners = ref({});
  // 连接到 MQTT 服务器  
 function connect() {
  console.log('2**********');
    if (client.value) return;  
    client.value = mqtt.connect('地址',mqttConfig);  
    client.value.on('connect', () => {  
      console.log('Connected to MQTT');
      return true
      // 这里可以添加默认的订阅
      // client.value.subscribe('xxxx')
    });  
    client.value.on('message', (topic, message) => {
      if (listeners.value[topic]) {
        listeners.value[topic].forEach(callback => callback(message.toString()))
      }  
    });
    // 处理错误和断开连接的情况  
    client.value.on('error', (error) => {  
      console.error('MQTT error:', error);  
    });  
    client.value.on('close', () => {  
      console.log('MQTT connection closed');  
      client.value = null; // 断开连接后重置 client  
    });  
  }  
  // 断开 MQTT 连接  
  function disconnect() {  
    if (client.value) {  
      client.value.end();  
      client.value = null;  
    }  
  }  
  // 订阅 MQTT 主题  
  function subscribe(topic, callback) {  
    console.log(topic)
    if (client.value && client.value.connected) {  
      client.value.subscribe(topic);  
  
      if (!listeners.value[topic]) {  
        listeners.value[topic] = [];  
      }  
      listeners.value[topic].push(callback);  
    }
  }
  // 取消订阅 MQTT 主题  
  function unsubscribe(topic, callback) {  
    if (client.value && client.value.connected && listeners.value[topic]) {  
      const index = listeners.value[topic].indexOf(callback);  
      if (index > -1) {  
        listeners.value[topic].splice(index, 1);  
  
        // 如果没有监听者了，可以取消订阅  
        if (listeners.value[topic].length === 0) {  
          client.value.unsubscribe(topic);  
        }  
      }  
    }  
  }  
  // 发布 MQTT 消息  
  function publish(topic, message) {  
    if (client.value && client.value.connected) {  
      client.value.publish(topic, message);  
    }  
  }