Vue--keep-alive使用实例详解
作者：IT利刃出鞘
这篇文章主要介绍了Vue--keep-alive使用实例详解,keep-alive标签主要用于保留组件状态或避免重新渲染，用示例代码介绍Vue的keep-alive的用法，需要的朋友可以参考下
简介
说明
本文用示例介绍Vue的keep-alive的用法。
keep-alive标签主要用于保留组件状态或避免重新渲染。
官网网址
https://v2.cn.vuejs.org/v2/api/#keep-alive
相关网址
公共代码
路由（router/index.js）
import Vue from 'vue'
import VueRouter from 'vue-router'
import Parent from '../components/Parent'
Vue.use(VueRouter)
const routes = [
{
path: '/',
name: 'Parent',
component: Parent
}
]
const router = new VueRouter({
routes
})
export default router生命周期mixin（mixins/LifeCycle.js）
下边的两个页面组件都要打印生命周期，所以我把它抽出作为mixin。
export default {
computed: {
name () {
return this.$options.name
}
},
created () {
console.log('created ==> ' + this.name)
},
activated () {
console.log('activated ==> ' + this.name)
},
deactivated () {
console.log('deactivated ==> ' + this.name)
},
destroyed () {
console.log('destroyed ==> ' + this.name)
}
}子页面组件
components/CompA.vue
<template>
<div class="outer">
<div>
这是CompA
</div>
</div>
</template>
<script>
import LifeCycle from '../mixins/LifeCycle'
export default {
name: 'CompA',
mixins: [LifeCycle]
}
</script>
<style scoped>
.outer {
margin: 20px;
border: 2px solid blue;
padding: 20px;
}
</style>components/CompB.vue
<template>
<div class="outer">
这是CompB
</div>
</template>
<script>
import LifeCycle from '../mixins/LifeCycle'
export default {
name: 'CompB',
mixins: [LifeCycle]
}
</script>
<style scoped>
.outer {
margin: 20px;
border: 2px solid blue;
padding: 20px;
}
</style>动态组件实例
不加keep-alive
代码
components/Parent.vue
<template>
<div class="outer">
<div>
这是Parent
</div>
<br>
<button @click="useCompA">切换到CompA</button>
|
<button @click="useCompB">切换到CompB</button>
<component :is="componentName"></component>
</div>
</template>
<script>
import CompA from './CompA'
import CompB from './CompB'
export default {
name: 'Parent',
components: {
CompA,
CompB
},
data () {
return {
componentName: ''
}
},
methods: {
useCompA () {
this.componentName = 'CompA'
},
useCompB () {
this.componentName = 'CompB'
}
}
}
</script>
<style scoped>
.outer {
margin: 20px;
border: 2px solid red;
padding: 20px;
}
</style>测试
访问：http://localhost:8080/#/
可以发现：进入组件时调用created；离开组件时调用destroyed。
加keep-alive
代码
component/Parent.vue
将动态组件用keep-alive标签包起来。
<template>
<div class="outer">
<div>
这是Parent
</div>
<br>
<button @click="useCompA">切换到CompA</button>
|
<button @click="useCompB">切换到CompB</button>
<keep-alive>
<component :is="componentName"></component>
</keep-alive>
</div>
</template>
<script>
import CompA from './CompA'
import CompB from './CompB'
export default {
name: 'Parent',
components: {
CompA,
CompB
},
data () {
return {
componentName: ''
}
},
methods: {
useCompA () {
this.componentName = 'CompA'
},
useCompB () {
this.componentName = 'CompB'
}
}
}
</script>
<style scoped>
.outer {
margin: 20px;
border: 2px solid red;
padding: 20px;
}
</style>测试
访问：http://localhost:8080/#/
可以发现：进入组件时调用created、activated；离开组件时调用deactivated（不调用destroyed）。
router-view实例
不加keep-alive
代码
修改路由设置（router/index.js）
import Vue from 'vue'
import VueRouter from 'vue-router'
import Parent from '../components/Parent'
import CompA from '../components/CompA'
import CompB from '../components/CompB'
Vue.use(VueRouter)
const routes = [
{
path: '/',
name: 'Parent',
component: Parent
},
{
path: '/compA',
name: 'CompA',
component: CompA
},
{
path: '/compB',
name: 'CompB',
component: CompB
}
]
const router = new VueRouter({
routes
})
export default router修改入口组件（components/Parent.vue）
<template>
<div class="outer">
<div>
这是Parent
</div>
<br>
<router-link :to="{name: 'CompA'}">跳转到CompA</router-link>
|
<router-link :to="{name: 'CompB'}">跳转到CompB</router-link>
<router-view></router-view>
</div>
</template>
<script>
export default {
name: 'Parent'
}
</script>
<style scoped>
.outer {
margin: 20px;
border: 2px solid red;
padding: 20px;
}
</style>测试
访问：http://localhost:8080/#/
可以发现：进入路由组件时调用created；离开路由组件时调用destroyed。
加keep-alive（加到App.vue里）
修改App.vue
将router-view标签包裹在keep-alive标签里。
<template>
<div id="app">
<div id="nav">
<router-link to="/">Home</router-link>
|
<router-link to="/about">About</router-link>
</div>
<!-- 原来写法 -->
<!-- <router-view/> -->
<keep-alive>
<router-view/>
</keep-alive>
</div>
</template>
<style>
<!-- 省略 -->
</style>测试
访问：http://localhost:8080/#/
可以发现：进入组件时调用created、activated；离开组件时调用deactivated（不调用destroyed）。
加keep-alive（加到Parent.vue里）
说明
需要做如下两步：
- Parent.vue：将router-view包裹在keep-alive里边
- 将CompA和CompB的路由作为Parent的嵌套路由（Children）
如果只修改Parent.vue，将router-view包裹在keep-alive里边，这样是没用的，跟没有加keep-alive效果一样。
代码
修改components/Parent.vue
<template>
<div class="outer">
<div>
这是Parent
</div>
<br>
<router-link :to="{name: 'CompA'}">跳转到CompA</router-link>
|
<router-link :to="{name: 'CompB'}">跳转到CompB</router-link>
<keep-alive>
<router-view></router-view>
</keep-alive>
</div>
</template>
<script>
export default {
name: 'Parent'
}
</script>
<style scoped>
.outer {
margin: 20px;
border: 2px solid red;
padding: 20px;
}
</style>修改路由（router/index.js）
import Vue from 'vue'
import VueRouter from 'vue-router'
import Parent from '../components/Parent'
import CompA from '../components/CompA'
import CompB from '../components/CompB'
Vue.use(VueRouter)
const routes = [
{
path: '/',
name: 'Parent',
component: Parent,
children: [
{
path: '/compA',
name: 'CompA',
component: CompA
},
{
path: '/compB',
name: 'CompB',
component: CompB
}
]
}
]
const router = new VueRouter({
routes
})
export default router测试
访问：http://localhost:8080/#/
到此这篇关于Vue--keep-alive使用实例详解的文章就介绍到这了,更多相关Vue--keep-alive使用内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家！