Vue父组件与子组件传递事件/调用事件

<template>
<div>
<div @click="openChild">弹弹弹，弹出子组件</div>
<childs ref="alert" @watchChild="parentReceive"></childs> <!--监听子组件绑定的方法-->
</div>
</template>

<script>
import childs from '../components/modal/Alert'
export default{
data(){
return {
    msg: '我是父组件的msg！！！'
}
},
components:{
    childs
},
methods:{
parentReceive(message){
    alert(message);
},
openChild(){
    this.$refs.alert.open('我是子组件','子组件内容！！！！！');
}
}
}
</script>

<style>
</style>
子组件：

<template>
<modal :show='show' ref="modal">
<div slot="title">{{title}}</div>
<div slot="content">{{content}}</div>
<div slot="buttons" class="modal-buttons">
<span class="modal-button" @click="_onClick()">确定</span>
</div>
</modal>
</template>

<script>
import Modal from './Modal'

export default {
props: {
show: {
    type: Boolean,
    default: false
},
okText: {
    type: String,
    default: '确定'
},
},
data(){
    return {
        title: '',
        content: ''
    }
},
components: {
Modal
},
methods: {
open (title, content) {
    this.title = title
    this.content = content
    this.$refs.modal.open()
},
close () {
    this.title = ''
    this.content = ''
    this.$refs.modal.close()
},
_onClick(){
this.close();
this.$emit('watchChild','我是从子组件传过来的内容！！！');    //触发$emit绑定的watchChild方法
}
}
}
</script>
第一种方法：

<template>
<div>
<div @click="openChild">弹弹弹，弹出子组件</div>
<childs ref="alert" :on-ok="parentReceive"></childs> <!--把父组件的方法名传给子组件的onOK属性-->
</div>
</template>

<script>
import childs from '../components/modal/Alert'
export default{
data(){
    return {
        msg: '我是父组件的msg！！！'
    }
},
components:{
    childs
},
methods:{
parentReceive(message){
    alert(message);
},
openChild(){
    this.$refs.alert.open('我是子组件','子组件内容！！！！！');
}
}
}
</script>

<style>
</style>
子组件：

<template>
<modal :show='show' ref="modal">
<div slot="title">{{title}}</div>
<div slot="content">{{content}}</div>
<div slot="buttons" class="modal-buttons">
<span class="modal-button" @click="_onClick()">确定</span>
</div>
</modal>
</template>

<script>
import Modal from './Modal'

export default {
props: {
show: {
    type: Boolean,
    default: false
},
okText: {
    type: String,
    default: '确定'
},
onOk: {    //定义onOK属性
    type: Function
}
},
data(){
return {
    title: '',
    content: ''
}
},
components: {
    Modal
},
methods: {
open (title, content) {
    this.title = title
    this.content = content
    this.$refs.modal.open()
},
close () {
    this.title = ''
    this.content = ''
    this.$refs.modal.close()
},
_onClick(){
this.close();
if(this.onOk){
    this.onOk('我是子组件传递过来的数据！！！！');
}
}
}
}
</script>
第二种方法：