DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Titletitle>
<script src="https://unpkg.com/vue@3/dist/vue.global.js">script>
<style>
.dvcolor {
color: red;
}
.dvgreen{
color: green;
}
style>
head>
<body>
<div id="app">
<div :class="dvcls" @click="change">
<h1>你的心情h1>
div>
div>
body>
<script>
// 引入
const {createApp, ref} = Vue
// 创建
createApp({
//setup 标记 Vue3 支持Vue3的语法 直接定义变量、函数都可以
setup() {
const dvcls = ref("dvcolor")
const change = () => {
console.log(dvcls.value)
if (dvcls.value == "dvcolor") {
dvcls.value = "dvgreen"
} else {
dvcls.value = "dvcolor"
}
}
return {//只有返回的上面才可以使用
dvcls,change
}
}
}).mount('#app')
script>
html>


DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Titletitle>
<script src="https://unpkg.com/vue@3/dist/vue.global.js">script>
<style>
.dvcolor {
color: red;
}
.dvgreen {
color: green;
}
style>
head>
<body>
<div id="app">
<div :class="dvcls" @click="change">
<h1>你的心情h1>
div>
div>
body>
<script>
// 引入
const {createApp, ref} = Vue
// 创建
createApp({
//setup 标记 Vue3 支持Vue3的语法 直接定义变量、函数都可以
setup() {
const dvcls = ref("dvcolor")
var t;
const change = () => {
console.log(dvcls.value)
if (t != null) {
//js 关闭定时任务
clearInterval(t)
} else {
//js 开启定时任务
t = setInterval(() => {
if (dvcls.value == "dvcolor") {
dvcls.value = "dvgreen"
} else {
dvcls.value = "dvcolor"
}
}, 1000)
}
if (dvcls.value == "dvcolor") {
dvcls.value = "dvgreen"
} else {
dvcls.value = "dvcolor"
}
}
return {//只有返回的上面才可以使用
dvcls, change
}
}
}).mount('#app')
script>
html>