前言
Vue 作爲現在比較火的框架之一，相信您在使用的過程中，也會遇到組件間傳值的情況，本文將講解幾種 Vue 組件間傳值的幾種方法，跟着小編一起來學習一下吧！
實現
注意： 學習本文，需要您對 Vue 有一定的瞭解。
爲了便於講解，以下方法均假設父組件是 FatherComponent，子組件是 ChildComponent，兄弟組件是：BrotherComponent。我們來假定一種場景：點擊父組件“傳遞給子組件”按鈕，向子組件傳遞一條消息“I am your father.”；點擊子組件“傳遞給父組件”按鈕，向父組件傳遞一條消息“I am your child.”；點擊子組件“傳遞給兄弟組件”按鈕，向兄弟組件傳遞一條消息“I am your brother.”
方法一
關鍵詞： props、$emit
父組件 FatherComponent 代碼：
<template>
<div>
<div>{{toFatherInfo}}</div>
<ChildComponent :toChildInfo="toChildInfo" @toFather="toFather" @toBrother="toBrother"/>
<BrotherComponent :toBrotherInfo="toBrotherInfo"/>
<button @click="toChild">傳遞給子組件</button>
</div>
</template>
<script>
import ChildComponent from 'components/test/child-component'
import BrotherComponent from 'components/test/brother-component'
export default {
components: {
ChildComponent,
BrotherComponent
},
data () {
return {
toFatherInfo: '',
toChildInfo: '',
toBrotherInfo: ''
}
},
methods: {
toFather (res) {
this.toFatherInfo = res
},
toBrother (res) {
this.toBrotherInfo = res
},
toChild () {
this.toChildInfo = 'I am your father.'
}
}
}
</script>
<style lang="less">
button {
font-size: 36px;
border: none;
padding: 20px;
background-color: #999;
color: #fff;
width: 100%;
margin-top: 30px;
}
</style>
子組件 ChildComponent 代碼：
<template>
<div>
<div>{{toChildInfo}}</div>
<button @click="toFather">傳遞給父組件</button>
<button @click="toBrother">傳遞給兄弟組件</button>
</div>
</template>
<script>
export default {
props: {
toChildInfo: {
type: String
}
},
methods: {
toFather () {
this.$emit('toFather', 'I am your child.')
},
toBrother () {
this.$emit('toBrother', 'I am your brother.')
}
}
}
</script>
<style lang="less">
</style>
兄弟組件 BrotherComponent 代碼：
<template>
<div>{{toBrotherInfo}}</div>
</template>
<script>
export default {
props: {
toBrotherInfo: {
type: String
}
}
}
</script>
<style lang="less">
</style>
通過上面代碼，不難發現，我們通過使用 props 來實現父組件給子組件傳值；子組件向父組件傳值時，藉助 $emit 來實現；而子組件向兄弟組件傳值時，將兩者結合起來使用。
方法二
關鍵詞：獨立的事件中心 eventHub
首先需要先創建 eventHub.js 文件，代碼如下：
// 將在各處使用該事件中心
// 組件通過它來通信
import Vue from 'vue'
export default new Vue()然後在組件中，可以使用 $emit, $on, $off 分別來分發、監聽、取消監聽事件。
父組件 FatherComponent 代碼：
<template>
<div>
<div>{{info}}</div>
<ChildComponent />
<BrotherComponent />
<button @click="toChild">傳遞給子組件</button>
</div>
</template>
<script>
import eventHub from '../../components/test/eventHub'
import ChildComponent from 'components/test/child-component'
import BrotherComponent from 'components/test/brother-component'
export default {
components: {
ChildComponent,
BrotherComponent
},
data () {
return {
info: ''
}
},
created: function () {
eventHub.$on('toFather', this.toFather)
},
// 最好在組件銷燬前
// 清除事件監聽
beforeDestroy: function () {
eventHub.$off('toFather', this.toFather)
},
methods: {
toFather (res) {
this.info = res
},
toChild () {
eventHub.$emit('toChild', 'I am your father.')
}
}
}
</script>
<style lang="less">
button {
font-size: 36px;
border: none;
padding: 20px;
background-color: #999;
color: #fff;
width: 100%;
margin-top: 30px;
}
</style>
子組件 ChildComponent 代碼：
<template>
<div>
<div>{{info}}</div>
<button @click="toFather">傳遞給父組件</button>
<button @click="toBrother">傳遞給兄弟組件</button>
</div>
</template>
<script>
import eventHub from './eventHub'
export default {
data () {
return {
info: ''
}
},
created: function () {
eventHub.$on('toChild', this.toChild)
},
// 最好在組件銷燬前
// 清除事件監聽
beforeDestroy: function () {
eventHub.$off('toChild', this.toChild)
},
methods: {
toChild (res) {
this.info = res
},
toFather () {
eventHub.$emit('toFather', 'I am your child.')
},
toBrother () {
eventHub.$emit('toBrother', 'I am your brother.')
}
}
}
</script>
<style lang="less">
</style>
兄弟組件 BrotherComponent 代碼：
<template>
<div>{{info}}</div>
</template>
<script>
import eventHub from './eventHub'
export default {
data () {
return {
info: ''
}
},
created: function () {
eventHub.$on('toBrother', this.toBrother)
},
// 最好在組件銷燬前
// 清除事件監聽
beforeDestroy: function () {
eventHub.$off('toBrother', this.toBrother)
},
methods: {
toBrother (res) {
this.info = res
}
}
}
</script>
<style lang="less">
</style>
方法三
關鍵詞：Vuex
我們需要創建 store.js 來存放數據：
import Vue from 'vue'
import Vuex from 'vuex'
Vue.use(Vuex)
export default new Vuex.Store({
state: {
fromFatherInfo: '',
fromChildInfo: '',
fromBrotherInfo: ''
},
mutations: {
changeFromFatherInfo (state, fromFatherInfo) {
state.fromFatherInfo = fromFatherInfo
},
changeFromChildInfo (state, fromChildInfo) {
state.fromChildInfo = fromChildInfo
},
changeFromBrotherInfo (state, fromBrotherInfo) {
state.fromBrotherInfo = fromBrotherInfo
}
}
})
實例化：
import Vue from 'vue'
import App from './App'
import store from './store'
new Vue({
el: '#app',
store,
template: '<App/>',
components: { App }
})父組件 FatherComponent 代碼：
<template>
<div>
<div>{{fromChildInfo}}</div>
<ChildComponent />
<BrotherComponent />
<button @click="toChild">傳遞給子組件</button>
</div>
</template>
<script>
import ChildComponent from 'components/test/child-component'
import BrotherComponent from 'components/test/brother-component'
export default {
components: {
ChildComponent,
BrotherComponent
},
computed: {
fromChildInfo () {
return this.$store.state.fromChildInfo
}
},
methods: {
toChild () {
this.$store.commit('changeFromFatherInfo', 'I am your father.')
}
}
}
</script>
<style lang="less">
button {
font-size: 36px;
border: none;
padding: 20px;
background-color: #999;
color: #fff;
width: 100%;
margin-top: 30px;
}
</style>子組件 ChildComponent 代碼：
<template>
<div>
<div>{{fromFatherInfo}}</div>
<button @click="toFather">傳遞給父組件</button>
<button @click="toBrother">傳遞給兄弟組件</button>
</div>
</template>
<script>
export default {
computed: {
fromFatherInfo () {
return this.$store.state.fromFatherInfo
}
},
methods: {
toFather () {
this.$store.commit('changeFromChildInfo', 'I am your child.')
},
toBrother () {
this.$store.commit('changeFromBrotherInfo', 'I am your brother.')
}
}
}
</script>
<style lang="less">
</style>
兄弟組件 BrotherComponent 代碼：
<template>
<div>{{fromBrotherInfo}}</div>
</template>
<script>
export default {
computed: {
fromBrotherInfo () {
return this.$store.state.fromBrotherInfo
}
}
}
</script>
<style lang="less">
</style>