Vue CSS 动画原理与 Transition 组件详解

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Vue中css动画原理</title>
  <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
  <style>
    .fade-enter, .fade-leave-to {
      opacity: 0;
    }
    .fade-enter-active, .fade-leave-active {
      transition: opacity 1s;
    }
  </style>
</head>
<body>
<div id="app">
  <transition name="fade">
    <div v-if="show">hello world!</div>
  </transition>
  <button @click="handleBtnClick">change</button>
</div>
</body>
</html>
<script>
  var vm = new Vue({
    el: '#app',
    data: {
      show: true
    },
    methods: {
      handleBtnClick: function () {
        this.show = !this.show
      }
    }
  })
</script>