vue03 vue生命周期
1 事件处理之按键修饰符
# 键盘有很多键， 回车，esc.... 按下或者抬起能够触发某个事件(函数执行)
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="./js/vue.js"></script>
</head>
<body>
<div id="app">
普通使用：<input type="text" v-model="myText" @keydown="handleDown($event)">
<hr>
监控enter键：<input type="text" v-model="myText" @keydown.enter="handleDown1()">
</div>
</body>
<script>
new Vue({
el: '#app',
data: {
myText: ''
},
methods: {
handleDown(event) {
console.log(event.key)
},
handleDown1() {
console.log('enter被按了')
}
}
})
</script>
</html>
2 表单控制之checkbox单选多选和radio
<!DOCTYPE html>
<html lang="en">
<head>
<h1>我老刘最牛逼,最帅</h1>
<meta charset="UTF-8">
<title>Title</title>
<script src="./js/vue.js"></script>
</head>
<body>
<div id="app">
<h1>checkbox单选---使用布尔</h1>
<input type="text" placeholder="请输入用户名" v-model="username">
<br>
<input type="password" placeholder="请输入密码" v-model="password">
<br>
记住密码：<input type="checkbox" v-model="check_rem">
<h1>checkbox多选---使用数组</h1>
爱好:
<br>
<input type="checkbox" v-model="check_many" value="1">喝酒
<input type="checkbox" v-model="check_many" value="2">烫头
<input type="checkbox" v-model="check_many" value="3">抽烟
<input type="checkbox" v-model="check_many" value="4">睡觉
<hr>
{{check_many}}
<h1>radio---使用字符串</h1>
<input type="text" placeholder="请输入用户名" v-model="username">
<br>
<input type="password" placeholder="请输入密码" v-model="password">
<br>
性别：
<input type="radio" v-model="gender" value="1">男
<input type="radio" v-model="gender" value="2">女
<input type="radio" v-model="gender" value="0">未知
<hr>
{{gender}}
</div>
</body>
<script>
var vm = new Vue({
el: '#app',
data: {
username: '',
password: '',
check_rem: false,
check_many: [],
gender:''
},
methods: {}
})
</script>
</html>
3 基本购物车
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
<script src="./js/vue.js"></script>
</head>
<body>
<div id="app">
<div class="row">
<div class="col-md-6 col-md-offset-3">
<h1>基本购物车</h1>
<table class="table table-striped">
<thead>
<tr>
<th>商品名</th>
<th>商品价格</th>
<th>商品数量</th>
<th>选择</th>
</tr>
</thead>
<tbody>
<tr v-for="item in dataList">
<th scope="row">{{item.name}}</th>
<td>{{item.price}}</td>
<td>{{item.number}}</td>
<td><input type="checkbox" v-model="checkGroup" :value="item"></td>
</tr>
</tbody>
</table>
<hr>
总价格是：{{getPrice()}}
<br>
选中了：{{checkGroup}}
</div>
</div>
</div>
</body>
<script>
var vm = new Vue({
el: '#app',
data: {
dataList: [
{name: '金瓶没', price: 99, number: 2},
{name: '钢板', price: 59, number: 1},
{name: '水壶转', price: 89, number: 5},
{name: '特斯拉', price: 230000, number: 3},
],
checkGroup: []
},
methods: {
getPrice() {
var total = 0
// 循环方式一
// for (i = 0; i < this.checkGroup.length; i++) {
// total += this.checkGroup[i].price * this.checkGroup[i].number
// }
// 循环方式二 对象，数组的方法
// this.checkGroup.forEach(function (value,index){
// total+=value.price*value.number
// })
// 循环方式三
// for (i in this.checkGroup){ // i 是索引
// total += this.checkGroup[i].price * this.checkGroup[i].number
// }
// 循环方式四
for (item of this.checkGroup) { // item 是索引
total += item.price * item.number
}
return total
}
}
})
</script>
</html>
4 带多选，单选购物车
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
<script src="./js/vue.js"></script>
</head>
<body>
<div id="app">
<div class="row">
<div class="col-md-6 col-md-offset-3">
<h1>基本购物车</h1>
<table class="table table-striped">
<thead>
<tr>
<th>商品名</th>
<th>商品价格</th>
<th>商品数量</th>
<th>全选/全不选 <input type="checkbox" v-model="checkAll" @change="handleCheckAll"></th>
</tr>
</thead>
<tbody>
<tr v-for="item in dataList">
<th scope="row">{{item.name}}</th>
<td>{{item.price}}</td>
<td><button @click="item.number++">+</button>{{item.number}}<button @click="reduceNum(item)">-</button></td>
<td><input type="checkbox" v-model="checkGroup" :value="item" @change="handleOne"></td>
</tr>
</tbody>
</table>
<hr>
总价格是：{{getPrice()}}
<br>
选中了：{{checkGroup}}
<br>
{{checkAll}}
</div>
</div>
</div>
</body>
<script>
var vm = new Vue({
el: '#app',
data: {
dataList: [
{name: '金瓶没', price: 99, number: 2},
{name: '钢板', price: 59, number: 1},
{name: '水壶转', price: 89, number: 5},
{name: '特斯拉', price: 230000, number: 3},
],
checkGroup: [],
checkAll: false
},
methods: {
getPrice() {
var total = 0
for (item of this.checkGroup) { // item 是索引
total += item.price * item.number
}
return total
},
handleCheckAll() {
if (this.checkAll) {// 全选中
this.checkGroup = this.dataList
} else {
this.checkGroup = []
}
},
handleOne() {
// if (this.checkGroup.length == this.dataList.length) {
// this.checkAll = true
// } else {
// this.checkAll = false
// }
this.checkAll = (this.checkGroup.length === this.dataList.length)
},
reduceNum(item){
if(item.number<=1){
alert('不能再少了，受不了了')
}else {
item.number--
}
}
}
})
</script>
</html>
5 数量加减购物车
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
<script src="./js/vue.js"></script>
</head>
<body>
<div id="app">
<div class="row">
<div class="col-md-6 col-md-offset-3">
<h1>基本购物车</h1>
<table class="table table-striped">
<thead>
<tr>
<th>商品名</th>
<th>商品价格</th>
<th>商品数量</th>
<th>全选/全不选 <input type="checkbox" v-model="checkAll" @change="handleCheckAll"></th>
</tr>
</thead>
<tbody>
<tr v-for="item in dataList">
<th scope="row">{{item.name}}</th>
<td>{{item.price}}</td>
<td>{{item.number}}</td>
<td><input type="checkbox" v-model="checkGroup" :value="item" @change="handleOne"></td>
</tr>
</tbody>
</table>
<hr>
总价格是：{{getPrice()}}
<br>
选中了：{{checkGroup}}
<br>
{{checkAll}}
</div>
</div>
</div>
</body>
<script>
var vm = new Vue({
el: '#app',
data: {
dataList: [
{name: '金瓶没', price: 99, number: 2},
{name: '钢板', price: 59, number: 1},
{name: '水壶转', price: 89, number: 5},
{name: '特斯拉', price: 230000, number: 3},
],
checkGroup: [],
checkAll: false
},
methods: {
getPrice() {
var total = 0
for (item of this.checkGroup) { // item 是索引
total += item.price * item.number
}
return total
},
handleCheckAll() {
if (this.checkAll) {// 全选中
this.checkGroup = this.dataList
} else {
this.checkGroup = []
}
},
handleOne() {
// if (this.checkGroup.length == this.dataList.length) {
// this.checkAll = true
// } else {
// this.checkAll = false
// }
this.checkAll = (this.checkGroup.length === this.dataList.length)
}
}
})
</script>
</html>
6 v-model进阶
# lazy：等待input框的数据绑定失去焦点之后再变化
# number：数字开头，只保留数字，后面的字母不保留；字母开头，都保留
# trim：去除首位的空格
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="./js/vue.js"></script>
</head>
<body>
<div id="app">
lazy的使用：<input type="text" v-model.lazy="myText">--->{{myText}}
<hr>
number的使用：<input type="text" v-model.number="myText2">--->{{myText2}}
<hr>
trim的使用：<input type="text" v-model.trim="myText3">--->{{myText3}}
</div>
</body>
<script>
new Vue({
el: '#app',
data: {
myText: '',
myText2: '',
myText3: '',
},
})
</script>
</html>
7 vue生命周期
# 组件化开发---》页面也是一个组件---》一个组件就是一个Vue的对象----》Vue对象是有生命周期---》从创建那一刻到销毁的过程叫生命周期
# 生命周期的8个钩子函数 ---》当执行到那，就会执行某个钩子函数
beforeCreate 创建Vue实例之前调用
created 创建Vue实例成功后调用（可以在此处发送异步请求后端数据）
beforeMount 渲染DOM之前调用
mounted 渲染DOM之后调用
beforeUpdate 重新渲染之前调用（数据更新等操作时，控制DOM重新渲染）
updated 重新渲染完成之后调用
beforeDestroy 销毁之前调用
destroyed 销毁之后调用
# AOP 面向切面编程 ----》
# OOP 面向对象编程
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="./js/vue.js"></script>
</head>
<body>
<div id="app">
<button @click="handleShow">点我组件显示和消失</button>
<Child v-if="show"></Child>
</div>
</body>
<script>
// 创建一个组件
Vue.component('Child', {
template: `
<div>
<h1>{{ name }}</h1>
<button @click="handleClick">点我看美女</button>
</div>
`,
data() {
return {
name: 'lqz',
t:'',
}
},
methods: {
handleClick() {
alert('美女')
}
},
beforeCreate(){
console.log('beforeCreate')
},
created(){
console.log('created')
console.log('这个用的多，只要创建，data变量就初始化完成了，一般是从后端获取到的，在此处发送ajax请求')
// 延迟任务，延迟几秒执行某个函数
// setTimeout(()=>{
// alert('lqz is handsome')
// },3000)
// 定时任务，每个几秒，执行一次
this.t=setInterval(()=>{
console.log('3s结束了')
},3000)
},
beforeMount(){
console.log('beforeMount')
},
mounted(){
console.log('mounted')
},
beforeUpdate(){
console.log('beforeUpdate')
},
updated(){
console.log('updated')
},
beforeDestroy(){
console.log('beforeDestroy')
console.log('可能会有，组件销毁，清理资源')
clearInterval(this.t)
this.t=null
},
destroyed(){
console.log('destroyed')
}
})
new Vue({
el: '#app',
data: {
show: false,
},
methods:{
handleShow(){
this.show=!this.show
}
}
})
</script>
</html>
本文来自博客园，作者：{Mr_胡萝卜须}，转载请注明原文链接：https://www.cnblogs.com/Mr-fang/p/16464122.html
