DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>更新时的一个问题title>
<script type="text/javascript" src="/02_Vue模板语法/vue.js">script>
head>
<body>
<div id="root">
<h2>人员列表h2>
<button @click="updateMei">更新马冬梅的信息button>
<ul>
<li v-for="(p,index) of persons" :key="p.id">
{{p.name}}-{{p.age}}-{{p.sex}}
li>
ul>
div>
<script type="text/javascript">
Vue.config.productionTip = false
const vm = new Vue({
el:'#root',
data:{
persons:[
{id:'001',name:'马冬梅',age:30,sex:'女'},
{id:'002',name:'周冬雨',age:31,sex:'女'},
{id:'003',name:'周杰伦',age:18,sex:'男'},
{id:'004',name:'温兆伦',age:19,sex:'男'}
]
},
methods: {
updateMei(){
// this.persons[0].name = '马老师' //奏效
// this.persons[0].age = 50 //奏效
// this.persons[0].sex = '男' //奏效
// this.persons[0] = {id:'001',name:'马老师',age:50,sex:'男'} //不奏效
this.persons.splice(0,1,{id:'001',name:'马老师',age:50,sex:'男'})
}
}
})
script>
html>

DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>Vue监测数据改变的原理title>
<script type="text/javascript" src="../js/vue.js">script>
head>
<body>
<div id="root">
<h2>学校名称:{{name}}h2>
<h2>学校地址:{{address}}h2>
div>
body>
<script type="text/javascript">
Vue.config.productionTip = false //阻止 vue 在启动时生成生产提示。
const vm = new Vue({
el:'#root',
data:{
name:'尚硅谷',
address:'北京',
student:{
name:'tom',
age:{
rAge:40,
sAge:29,
},
friends:[
{name:'jerry',age:35}
]
}
}
})
script>
html>

DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>Documenttitle>
head>
<body>
<script type="text/javascript" >
let data = {
name:'尚硅谷',
address:'北京',
}
//创建一个监视的实例对象,用于监视data中属性的变化
const obs = new Observer(data)
console.log(obs)
//准备一个vm实例对象
let vm = {}
vm._data = data = obs
function Observer(obj){
//汇总对象中所有的属性形成一个数组
const keys = Object.keys(obj)
//遍历
keys.forEach((k)=>{
Object.defineProperty(this,k,{
get(){
return obj[k]
},
set(val){
console.log(`${k}被改了,我要去解析模板,生成虚拟DOM.....我要开始忙了`)
obj[k] = val
}
})
})
}
script>
body>
html>
DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>Vue监测数据改变的原理title>
<script type="text/javascript" src="/02_Vue模板语法/vue.js">script>
head>
<body>
<div id="root">
<h1>学校信息h1>
<h2>学校名称:{{school.name}}h2>
<h2>学校地址:{{school.address}}h2>
<h2>校长是:{{school.leader}}h2>
<hr/>
<h1>学生信息h1>
<button @click="addSex">添加一个性别属性,默认值是男button>
<h2>姓名:{{student.name}}h2>
<h2 v-if="student.sex">性别:{{student.sex}}h2>
<h2>年龄:真实{{student.age.rAge}},对外{{student.age.sAge}}h2>
<h2>朋友们h2>
<ul>
<li v-for="(f,index) in student.friends" :key="index">
{{f.name}}--{{f.age}}
li>
ul>
div>
body>
<script type="text/javascript">
Vue.config.productionTip = false //阻止 vue 在启动时生成生产提示。
const vm = new Vue({
el:'#root',
data:{
school:{
name:'尚硅谷',
address:'北京',
},
student:{
name:'tom',
age:{
rAge:40,
sAge:29,
},
friends:[
{name:'jerry',age:35},
{name:'tony',age:36}
]
}
},
methods: {
addSex(){
// Vue.set(this.student,'sex','男')
this.$set(this.student,'sex','男')
}
}
})
script>
html>

代码学自尚硅谷