vue2.0父子组件通信(慕课网)

vue2.0

父传子：Props

子传父：子：emit(eventName)父on(eventName)

父访问子：ref

非父子组件通信 :https://vuefe.cn/guide/components.html#非父子组件通信

vue2.0 移除：1.dispatch()2.broadcast() 3.events

vue1.0

<template>
<div id="app">
<p>{{title}}</p>
<p v-text="title"></p>
<p v-text="title2"></p>
<p v-html="title2"></p>
</div>
</template>
<script>
export default {
data () {
return {
title: 'this is a title!',
title2: '<span>?<span> this is a title!'
}
}
}
</script>

{{title}}

和

v-text="title"

等同

export default

最后生成

new
vue({ 参数})

新的ES6写法等同于旧的写法

//新的ES6
data () {
return {
title: 'this is a title!'
}
}

//旧的写法
data: function (){
return {
title: 'this is a title!'
}
}

v-html

解析渲染html标签

v-for 及v-bind控制class、v-on绑定事件、v-model双向绑定

<template>
<div id="app">
<p>{{title}}</p>
<!-- <p v-text="title"></p> -->
<!-- <p v-text="title2"></p> -->
<!-- <p v-html="title2"></p> -->
<input v-model="newItem" v-on:keyup.enter="addNew">
<ul>
<li v-for = "item in items" v-bind:class="{finished: item.isFinished}" v-on:click="toggleFinished(item)">
{{item.label}}
</li>
</ul>
</div>
</template>
<script>
import Store from './store'
export default {
data () {
return {
title: 'this is a todolist!',
title2: '<span>?<span> this is a todolist!',
items: Store.fetch(),
newItem: ''
}
},
watch: {
items: {
handler (items) {
Store.save(i
f1dd
tems)
},
deep: true
}
},
methods: {
toggleFinished (item) {
item.isFinished = !item.isFinished
},
addNew () {
this.items.push({
label: this.newItem,
isFinished: false
})
this.newItem = ''
}
}
}
</script>

<style>
.finished{
text-decoration: underline;
}

html {
height: 100%;
}

body {
display: flex;
align-items: center;
justify-content: center;
height: 100%;
}

#app {
color: #2c3e50;
margin-top: -100px;
max-width: 600px;
font-family: Source Sans Pro, Helvetica, sans-serif;
text-align: center;
}

#app a {
color: #42b983;
text-decoration: none;
}

.logo {
width: 100px;
height: 100px
}
</style>

store.js

const STORAGE_KEY = 'todos-vuejs'
export default {
fetch () {
return JSON.parse(window.localStorage.getItem(STORAGE_KEY) || '[]')
},
save (items) {
window.localStorage.setItem(STORAGE_KEY, JSON.stringify(items))
}
}

v-bind:class

简写

:class

v-on:click

简写

@click

v-on:keyup.enter

简写

@keyup.enter

回车keyup事件

v-model

双向绑定

JSON.parse()和JSON.stringify()

parse

用于从一个字符串中解析出json
对象。例如

var str=’{“name”:”cpf”,”age”:”23”}’

经 JSON.parse(str) 得到：

Object: age:"23"
name:"cpf"
_proto_:Object

ps:单引号写在{}外，每个属性都必须双引号，否则会抛出异常

stringify

用于从一个对象解析出字符串，例如

var a={a:1,b:2}

经 JSON.stringify(a)得到：

“{“a”:1,”b”:2}”

自定义事件

使用 $on() 监听事件；

使用 $emit()在它上面触发事件；

使用 $dispatch()派发事件，事件沿着父链冒泡；

使用 $broadcast()广播事件，事件向下传导给所有的后代。

父组件向子组件传递

1、采用props

父组件

<component-a msgfromfather='you die!!!!'></component-a>

子组件

<template>
<div class="hello">
<h1>{{ msgfromfather }}</h1>
<button v-on:click="onClickMe">click!</button>
</div>
</template>

<script>
export default {
data () {
return {
}
},
props: ['msgfromfather'],
methods: {
onClickMe () {
console.log(this.msgfromfather)
}
}
}
</script>
<style scoped>
h1 {
color: #42b983;
}
</style>

props监听父组件传递过来的信息
传递过来后，可直接引用，就如已经传递过来数据塞到data


2、使用event,$broadcast()从父组件传递消息下去

父组件

<template>
<button v-on:click="talkToMyBoy('be a good boy')">talkToMyBoy</button>
</div>
</template>
<script>
import Store from './store'
import ComponentA from './components/componentA'
export default {
components: {
ComponentA
},
methods: {
talkToMyBoy (msg) {
//console.log(msg);
this.$broadcast('onAddnew',msg)
}
}
}
</script>

子组件

<template>
<div class="hello">
<h1>{{ listentomyfather }}</h1>
</div>
</template>
<script>
export default {
data () {
return {
listentomyfather: 'Hello from componentA!'
}
},
events: {
'onAddnew' (msg) {
//console.log(msg)
this.listentomyfather = msg
}
}
}
</script>

子组件向父组件传递

1.子组件emit()触发，父组件on()监听

<template>
<div class="hello">
<button v-on:click="onClickMe">telltofather</button>
</div>
</template>

<script>
export default {
methods: {
onClickMe () {
this.$emit('child-tell-me-something',this.msg)
}
}
}
</script>

父组件

<template>
<div id="app">
<p>child tell me: {{childWords}}</p>
<component-a v-on:child-tell-me-something='listenToMyBoy'></component-a>
</div>
</template>

<script>
import Store from './store'
import ComponentA from './components/componentA'
export default {
components: {
ComponentA
},
data () {
return {
childWords: ''
}
},
methods: {
listenToMyBoy (msg) {
this.childWords = msg
}
}
}
</script>

2.不使用v-on,使用event ,子组件$dispatch()，从子组件传递消息上去

子组件

<template>
<div class="hello">
<button v-on:click="onClickMe">talktomyfather</button>
</div>
</template>

<script>
export default {
methods: {
onClickMe () {
this.$dispatch('child-tell-me-something',this.msg)
}
}
}
</script>

父组件

<template>
<div id="app">
<p>child tell me: {{childWords}}</p>
<component-a></component-a>
</div>
</template>

<script>
import Store from './store'
import ComponentA from './components/componentA'
export default {
components: {
ComponentA
},
data () {
return {
childWords: ''
}
},
events: {
'child-tell-me-something' (msg) {
this.childWords = msg
}
}
}
</script>