1.通过npm加载vuex,创建store.js文件,然后在main.js中引入,store.js文件代码如下

 import Vue from 'vue'
import Vuex from 'vuex'
Vue.use(Vuex);
const state = {
author:'Wise Wang'
};
const mutations = {
newAuthor(state,msg){
state.author = msg
}
}
export default new Vuex.Store({
state,
mutations
})
2、父组件可以使用 props 把数据传给子组件(props是单向绑定的)。
<div id="app">
     <div>这是父组件的parentArray:{{parentArray}}</div>
     <my-component :child-array="parentArray"></my-component>
   </div>
   <script>
     Vue.component('my-component', {
       template: `
       <div>这是接收了父组件传递值的子组件的childArray: {{childArray}} <br>
           <button type="button" @click="changeArray">
           点击我改变父元素的parentArray</button>
         </div>`,
       props: ['childArray'],
       data () {
         return {
           counter: 1
         }
       },
       methods: {
         changeArray () {
           this.childArray.push(this.counter++)
         }
       }
     })
     new Vue({
       el: '#app',
       data: {
         parentArray: []
       }
     })
   </script>


3、子组件可以使用 $emit 触发父组件的自定义事件。

vm.$emit( event, arg ) //触发当前实例上的事件

vm.$on( event, fn );//监听event事件后运行 fn;

例如:子组件:

    <template>
      <div class="train-city">
        <h3>父组件传给子组件的toCity:{{sendData}}</h3>
        <br/><button @click='select(`大连`)'>点击此处将‘大连’发射给父组件</button>
      </div>
    </template>
    <script>
      export default {
        name:'trainCity',
        props:['sendData'], // 用来接收父组件传给子组件的数据
        methods:{
          select(val) {
            let data = {
              cityname: val
            };
            this.$emit('showCityName',data);//select事件触发后,自动触发showCityName事件
          }
        }
      }
    </script>

父组件:

    <template>
        <div>
            <div>父组件的toCity{{toCity}}</div>
            <train-city @showCityName="updateCity" :sendData="toCity"></train-city>
        </div>
    <template>
    <script>
      import TrainCity from "./train-city";
      export default {
        name:'index',
        components: {TrainCity},
        data () {
          return {
            toCity:"北京"
          }
        },
        methods:{
          updateCity(data){//触发子组件城市选择-选择城市的事件
            this.toCity = data.cityname;//改变了父组件的值
            console.log('toCity:'+this.toCity)
          }
        }
      }
    </script>
12-24 06:46