import PubSub from 'pubsub-js' //引入
PubSub.publish('delete', data) //发布消息
PubSub.subscribe('delete', function(data){ }); //订阅

import { Component } from 'react' 
import PubSub from "pubsub-js"; 
class App extends Component {
 
  SubscribeList = ['POSErrorMessage'];  // 订阅消息集合

  componentDidMount () {
    // 开启订阅消息
    this.SubscribeList.forEach(item => {
      PubSub.subscribe(item, this.subscribeCallback);  // 开启订阅
    })
  }

  componentWillUnmount() {
    this.SubscribeList.forEach(item => {
      // 取消消息订阅
      PubSub.unsubscribe(item);
    })
  }

  componentDidShow () {
    // 开启订阅消息加载等待进度, componentDidMount 添加消息订阅
    this.SubscribeList.forEach(item => {
      PubSub.subscribe(item, this.subsribeCallback);
    })
  }/**
   * 订阅的回调函数 @subscribeName 订阅的消息名称， @data 数据
   * */
  subsribeCallback = (subscribeName, data) => {
    if (subscribeName === 'POSErrorMessage') {
      
    }
  }

  // 在 App 类中的 render() 函数没有实际作用
  // 请勿修改此函数
  render () {
    return (
      <div></div>
    )
  }
}

export default App

import PubSub from "pubsub-js";

PubSub.publish('POSErrorMessage', '消息内容') //发布消息