<template>
 <div id="app">
 <ChildA/>
 <ChildB/>
 </div>
</template>

<script>
 import ChildA from './components/ChildA' // 导入A组件
 import ChildB from './components/ChildB' // 导入B组件

 export default {
 name: 'App',
 components: {ChildA, ChildB} // 注册A、B组件
 }
</script>

<style>
 #app {
 font-family: 'Avenir', Helvetica, Arial, sans-serif;
 -webkit-font-smoothing: antialiased;
 -moz-osx-font-smoothing: grayscale;
 text-align: center;
 color: #2c3e50;
 margin-top: 60px;
 }

 div {
 margin: 10px;
 }
</style>

<template>
 <div id="childA">
 <h1>我是A组件</h1>
 <button @click="transform">点我让B组件接收到数据</button>
 <p>因为你点了B，所以我的信息发生了变化：{{BMessage}}</p>
 </div>
</template>

<script>
 export default {
 data() {
 return {
 AMessage: 'Hello，B组件，我是A组件'
 }
 },
 computed: {
 BMessage() {
 // 这里存储从store里获取的B组件的数据
 return this.$store.state.BMsg
 }
 },
 methods: {
 transform() {
 // 触发receiveAMsg，将A组件的数据存放到store里去
 this.$store.commit('receiveAMsg', {
  AMsg: this.AMessage
 })
 }
 }
 }
</script>

<style>
 div#childA {
 border: 1px solid black;
 }
</style>

<template>
 <div id="childB">
 <h1>我是B组件</h1>
 <button @click="transform">点我让A组件接收到数据</button>
 <p>因为你点了A，所以我的信息发生了变化：{{AMessage}}</p>
 </div>
</template>

<script>
 export default {
 data() {
 return {
 BMessage: 'Hello，A组件，我是B组件'
 }
 },
 computed: {
 AMessage() {
 // 这里存储从store里获取的A组件的数据
 return this.$store.state.AMsg
 }
 },
 methods: {
 transform() {
 // 触发receiveBMsg，将B组件的数据存放到store里去
 this.$store.commit('receiveBMsg', {
  BMsg: this.BMessage
 })
 }
 }
 }
</script>

<style>
 div#childB {
 border: 1px solid green;
 }
</style>

import Vue from 'vue'
import Vuex from 'vuex'

Vue.use(Vuex)

const state = {
 // 初始化A和B组件的数据，等待获取
 AMsg: '',
 BMsg: ''
}

const mutations = {
 receiveAMsg(state, payload) {
 // 将A组件的数据存放于state
 state.AMsg = payload.AMsg
 },
 receiveBMsg(state, payload) {
 // 将B组件的数据存放于state
 state.BMsg = payload.BMsg
 }
}

export default new Vuex.Store({
 state,
 mutations
})