场景
在做的一个项目中多个页面都需要使用到mqtt接收消息，但这样的话每个页面就都需要连接一次mqtt，并且要再次配置options信息、订阅主题、接收消息，非常的不方便，因此琢磨将mqtt封装到vuex中，使其可以多页面通用，这样只需要连接订阅一次，接收到的消息可以存储在vuex中。
一、安装mqtt
npm install mqtt二、暴露出main.js中的vue实例
使用export default暴露出app
import { createApp } from 'vue'
import App from './App.vue'
import router from './router'
import store from './store'const app = createApp(App)app.use(ElementPlus)
app.use(store).use(router).mount('#app')export default app三、封装mqtt
import { createStore } from 'vuex'
import main from "../main";//main.ts文件中要暴露app
import router from '@/router';// 引入vuex
export default createStore({state: {topics: [],//订阅话题},mutations: {//mqtt服务MQTT_SERVICE(state, event){// mqtt连接成功main.config.globalProperties.$mqtt.on('connect', (e) => {console.log('连接成功:', e)// console.log(state.topics)main.config.globalProperties.$mqtt.subscribe(state.topics, { qos: 1 }, (error) => {if (!error) {console.log('订阅成功')} else {console.log('订阅失败')}})})// 接收消息处理main.config.globalProperties.$mqtt.on('message', (topic, message) => {console.log('收到来自', topic, '的消息', message.toString())})// 断开发起重连main.config.globalProperties.$mqtt.on('reconnect', (error) => {console.log('正在重连:', error)})// 链接异常处理main.config.globalProperties.$mqtt.on('error', (error) => {console.log('连接失败:', error)})},//发布消息MQTT_PUBLISH(state, {topic, msg}){console.log(topic)main.config.globalProperties.$mqtt.publish(topic, msg)},//断开MQTTMQTT_CLOSE(state, event){console.log('断开MQTT');main.config.globalProperties.$mqtt.end()},},actions: {},modules: {}
})四、编写mqtt配置文件
在src下的utils下新建一个js文件：mqttConfig.js
import $store from "@/store/index";
export function getOptions(){let options = {connectTimeout: 40000,clientId: 'mqttId',clean: true,username: admin,password: admin}return options
}export function setTopics(){//此处修改VUEX中的值建议通过actions、mutations修改state值$store.state.topics = [ 'topic01','topic02','topic03''topic04''topic05']
}五、页面引入并使用
这里是在一个所有页面都要用到的一个公共组件中引入使用的，也可以在main.js中使用（看引入方法二）
方法1. 公共组件中引用
import { computed, reactive, ref ,defineComponent, onMounted, onUnmounted } from 'vue-demi';
import $store from "@/store/index";//引入VUEX
import main from "../main";//main.ts文件中要暴露app
import { getOptions, setTopics } from "@/utils/mqttConfig.js"
import mqtt from 'mqtt'//引入mqtt
//mqtt链接地址
let mqttUrl = 'ws://broker.emqx.io:8084'
export default defineComponent ({name:'msgDisplay',setup(){onMounted(() => {//mqtt连接main.config.globalProperties.$mqtt = mqtt.connect(mqttUrl, getOptions())//设置订阅主题setTopics()//启动mqtt状态监听$store.commit('MQTT_SERVICE')})onUnmounted(() => {$store.commit('MQTT_CLOSE') //断开mqtt})return { }}
})
</script>方法2.
该方法需要在main中创建连接，在首页的渲染生命周期中启动mqtt状态监听
import { createApp } from 'vue'
import App from './App.vue'
import router from './router'
import store from './store'const app = createApp(App)import mqtt from 'mqtt'
import { getOptions, setTopics } from "./utils/mqttConfig.js"
let mqttUrl = 'ws://broker.emqx.io:8084'
//mqtt连接
app.config.globalProperties.$mqtt = mqtt.connect(mqttUrl, getOptions())
//设置订阅主题
setTopics()app.use(ElementPlus)
app.use(store).use(router).mount('#app')export default app首页.vue
<script>
import { onMounted, defineComponent, onUnmounted } from 'vue';
import $store from "@/store/index";
export default defineComponent ({setup(){onMounted(() => {//启动mqtt状态监听$store.commit('MQTT_SERVICE')})onUnmounted(() => {//关闭项目时断开mqtt//此处仅适用于从首页跳转到下一个页面后首页没有被销毁的情况,其它情况自行修改$store.commit('MQTT_CLOSE') })}
})
</script>
