<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title><script src="vue.js"></script><style>.a{animation: aa 1s;}.b{animation: aa 1s reverse;}@keyframes aa{0%{transform: scale(0);}50%{transform: scale(2);}100%{transform: scale(1);}}</style></head>
<body><div id="app">
<input type="checkbox"v-model="isShow"><transition enter-active-class="a" leave-active-class="b"><div v-if="isShow" style="text-align: center;">123</div></transition></div><script>new Vue({el:"#app",data:{isShow:true}})</script>
</body>
</html>效果
