14 vue之生命周期
1 钩子函数
create
let vm = new Vue()
mount
挂载，把div挂载到组件中
update
let vm = new Vue({
el: '#box',
data: {
isShow: true // 修改这个内容
},
methods: {
handleClick() {
console.log('我是根组件')
}
}
})
2 测试代码
DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>生命周期title>
<script src="https://cdn.bootcdn.net/ajax/libs/vue/2.6.12/vue.min.js">script>
head>
<body>
<div id="box">
<child v-if="isShow">child>
<br>
<button @click="terminate">删除子组件button>
<button @click="reborn">显示子组件button>
div>
body>
<script>
Vue.component('child', {
template: `
<div>
{{name}}
<button @click="name='Darker1'">更新数据1</button>
<button @click="name='Darker2'">更新数据2</button>
</div>`,
data() {
return {
name: 'Darker1',
}
},
beforeCreate() {
console.group('当前状态：beforeCreate')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
},
created() {
console.group('当前状态：created')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
},
beforeMount() {
console.group('当前状态：beforeMount')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
},
mounted() {
console.group('当前状态：mounted')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
//用的最多，向后端加载数据，创建定时器等
console.log("页面已被vue实例渲染, data, methods已更新");
console.log('mounted')
this.t = setInterval(function () {
console.log('daada')
}, 3000)
},
beforeUpdate() {
console.group('当前状态：beforeUpdate')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
},
updated() {
console.group('当前状态：updated')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
},
beforeDestroy() {
console.group('当前状态：beforeDestroy')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
},
destroyed() {
console.group('当前状态：destroyed')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
//组件销毁，清理定时器
clearInterval(this.t)
this.t = null
console.log('destoryed')
},
})
let vm = new Vue({
el: '#box',
data: {
isShow: true
},
methods: {
terminate() {
this.isShow = false
},
reborn() {
this.isShow = true
}
}
})
script>
html>
课堂案列：
DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>生命周期title>
<script src="./js/vue.js">script>
head>
<body>
<div id="box">
<child v-if="isShow">child>
<hr>
<button @click="terminate">删除子组件button>
<button @click="reborn">显示子组件button>
div>
body>
<script>
// 子组件 child 定义的组件，相当于一个标签，但是他有自己的模板和样式，事件
Vue.component('child', {
template: `
<div>
<button @click="handleClick">点我，name更新</button>
<br>
{{name}}
</div>
`,
data() {
return {
name: 'lqz',
t:''
}
},
methods:{
handleClick(){
this.name='彭于晏'
}
},
beforeCreate() {
console.group('当前状态：beforeCreate')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
},
created() {
console.group('当前状态：created')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
},
beforeMount() {
console.group('当前状态：beforeMount')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
},
mounted() {
console.group('当前状态：mounted')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
//用的最多，向后端加载数据，创建定时器等
console.log("页面已被vue实例渲染, data, methods已更新");
console.log('mounted')
// 定时器，每隔3s钟，打印daada
this.t = setInterval(function () {
console.log('daada')
}, 3000)
},
beforeUpdate() {
console.group('当前状态：beforeUpdate')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
},
updated() {
console.group('当前状态：updated')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
},
beforeDestroy() {
console.group('当前状态：beforeDestroy')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
},
destroyed() {
console.group('当前状态：destroyed')
console.log('当前el状态：', this.$el)
console.log('当前data状态：', this.$data)
console.log('当前name状态：', this.name)
//组件销毁，清理定时器
clearInterval(this.t)
this.t = null
console.log('destoryed')
},
})
let vm = new Vue({
el: '#box',
data: {
isShow: true
},
methods: {
terminate() {
this.isShow = false
},
reborn() {
this.isShow = true
}
},
})
script>
html>