如何使用vue定义组件之——子组件调用父组件数据-编程知识

如何使用vue定义组件之——子组件调用父组件数据

1.定义父子模板template

 <div class="container"><my-father></my-father><my-father></my-father><my-father></my-father><!-- 此处无法调用子组件，子组件必须依赖于父组件进行展示 --><!-- <my-children></my-children> --></div><template id="father"><div><h3>我是父组件</h3><h3>访问子组件的数据:</h3><h3>{{ msg }}</h3><h3>{{ name }}</h3><h3>{{ age }}</h3><h3>{{ user }}</h3><my-children></my-children><hr></div></template><template id="children"><div><h6>我是子组件</h6><h6>访问子组件的数据:</h6></div></template>

2.创建Vue实例，如何建立父子关系

<script>new Vue({el: '.container',components: {'my-father': {//父组件template: '#father',data() {return {msg: "",name: "",age: null,user: {id: null,username: ""}}},components: {'my-children': { //子组件，只能在 my-father中调该组件template: '#children',data() {return {msg: "welcome children!",name: "I'm a child!",age: 6,user: {id: 1001,username: 'admin'}}}}}}}})
</script>

技术：事件监听+事件触发

父组件在调用子组件时，监听子组件触发的自定义事件，并在父组件中定义回调方法，用来接收数据

    <template id="father"><div><h3>我是父组件</h3><h3>访问子组件的数据:</h3><h3>{{ msg }}</h3><h3>{{ name }}</h3><h3>{{ age }}</h3><h3>{{ user }}</h3><!-- 监听子组件触发的数据 --><my-children @e-child="getMsg"></my-children><hr></div></template>

在子组件中使用`vm.$emit(事件名,数据)`触发自定义事件，将当前获取的数据，传给父类

                components: {'my-children': { //子组件，只能在 my-father中调该组件template: '#children',data() {return {msg: "welcome children!",name: "I'm a child!",age: 6,user: {id: 1001,username: 'admin'}}},created() {//触发事件，向父组件传递数据this.$emit('e-child', this.msg,this.name,this.age,this.user)}}}

父类定义一个方法，获取数据：

new Vue({el: '.container',components: {'my-father': {//父组件template: '#father',data() {return {msg: "",name: "",age: null,user: {id: null,username: ""}}},methods: {getMsg(msg,name,age,user) {this.msg = msg;this.name = name;this.age = age;this.user = user;}}}}})

打印结果：