<p ref="p">Hello</p>
<children ref="children"></children>

this.$refs.p
this.$refs.children

<template>
 <div>
 <div ref="myDiv" v-for="(ITem, index) in arr" :key="index">{{item}}</div>
 </div>
</template>
 
<script>
export default {
 data() {
 return {
  arr: ['one', 'two', 'three', 'four']
 }
 },
 mounted() {
 console.LOG(this.$refs.myDiv)
 },
 methods: {}
}
</script>
 
<style lang="sass" scoPEd>
 
</style>

<template>
 <div>{{msg}}</div>
</template>
 
<script>
export default {
 data() {
 return {
  msg: '我是子组件'
 }
 },
 methods: {
 changeMsg() {
  this.msg = '变身'
 }
 }
}
</script>
 
<style lang="sass" scoped></style>

<template>
 <div @click="parentMethod">
 <children ref="children"></children>
 </div>
</template>
 
<script>
import children From 'components/children.vue'
export default {
 components: { 
 children 
 },
 data() {
 return {}
 },
 methods: {
 parentMethod() {
  this.$refs.children //返回一个对象
  this.$refs.children.changeMsg() // 调用children的changeMsg方法
 }
 }
}
</script>
 
<style lang="sass" scoped></style>