消息订阅与发布

    作用：任意组件间进行通信。
    安装：npm i pubsbu-js

    订阅与取消
    import pubsub from 'pubsub-js'
    mounted(){
        this.pubId = pubsub.subscribe('hello',(msgName, data) =>{
            log(data)
        })
    },
    beforeDistory(){
        pubsub.unsubscribe(this.pubId)
    }

    发布
    import pubsub from 'pubsub-js'
    pubsub.publish('hello', 'hello,vue')