cubic-bezier即三次贝塞尔，可以生成贝塞尔曲线，在css中主要是给transition以及animation提供过渡效果的速度曲线

cubic-bezier函数默认接受四个参数，cubic-bezier(x1,y1,x2,y2)，其中y1、y2是可以大于或小于0的，基于此可以做出一些缓冲的过渡效果

<template> <div class="menu"> <div v-for="item in menuList"> <div class="menu-item" @mouseover="mouseover($event, item)" @mouseleave="mouseleave">{{ item.name }}</div> </div> </div> <transition name="move"> <div id="sub-menu" ref="subMenu" v-show="show" @mousemove="overSub"> <div class="sub-menu-item" v-for="item in subMenuList"> {{ item.name }} </div> </div> </transition></template><script>import { ref } from ‘vue‘;export default { setup() { let menuList = ref([ { name: ‘cloud‘, children: [ { name: ‘cloud1‘ }, { name: ‘cloud2‘ } ] }, { name: ‘software‘, children: [ { name: ‘software1‘ }, { name: ‘software2‘ }, { name: ‘software3‘ } ] }, { name: ‘docs‘, children: [ { name: ‘docs1‘ }, { name: ‘docs2‘ } ] } ]); let subMenuList = ref([]); let show = ref(false); return { menuList, subMenuList, show }; }, methods: { mouseover(e, item) { this.subMenuList = item.children; this.$refs.subMenu.style.left = e.target.offsetLeft + ‘px‘; this.$refs.subMenu.style.height = `${43 * this.subMenuList.length}px`; this.show = true; }, mouseleave() { this.show = false; } }};</script><style scoped>.menu { display: flex;}.menu-item { height: 40px; width: fit-content; margin-left: 20px; font-size: 26px; font-weight: lighter; color: #aaa; cursor: pointer;}#sub-menu { position: absolute; font-size: 32px; font-weight: lighter; color: #000; border: solid 1px #ccc; padding: 15px; border-radius: 10px;}.move-enter-active,.move-leave-active { transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);}</style>

没有用原生的transition属性是因为v-if不支持，所以必须结合vue的transition组件

其中 cubic-bezier(0.175, 0.885, 0.32, 1.275);  是提供过渡效果的关键，可以看出整个菜单会有一个缓冲的过渡效果，视觉上也更加具有冲击力