认识Vue的动画原理

利用transition标签和一系列的动画类来控制标签的动画效果。

transition标签的本质是帮你添加和删除动画类的。

transition标签的name属性用来区别动画类的。（如果不添加name属性，那么transition标签会默认找v-enter-from等等的v开头的动画类属性）
<template>
  <div class="app">
    <div>
      <button @click="isShow = !isShow">切换</button>
    </div>

    <transition name="why">
      <h2 v-if="isShow">哈哈哈哈</h2>
    </transition>
  </div>
</template>

<script setup>
import { ref } from 'vue';

const isShow = ref(false)

</script>

<style scoped>

h2 {
  display: inline-block;
}

.why-enter-from,
.why-leave-to {
  opacity: 0;
  transform: scale(0.6);
}

.why-enter-to,
.why-leave-from {
  opacity: 1;
  transform: scale(1);
}

.why-enter-active,
.why-leave-active {
  transition: all 2s ease;
}

</style>

animation动画实现

和普通的使用帧动画差不多。利用@keyframe和animation来实现

<template>
  <div class="app">
    <div>
      <button @click="isShow = !isShow">切换</button>
    </div>

    <transition name="why">
      <h2 v-if="isShow">
        要是有些事我没说，地坛，你别以为是我忘了，我什么也没忘，但是有些事只适合收藏。不能说，也不能想，却又不能忘。它们不能变成语言，它们无法变成语言，一旦变成语言就不再是它们了。它们是一片朦胧的温馨与寂寥，是一片成熟的希望与绝望，它们的领地只有两处：心与坟墓。比如说邮票，有些是用于寄信的，有些仅仅是为了收藏。
      </h2>
    </transition>
  </div>
</template>

<script setup>
import { ref } from 'vue';

const isShow = ref(false)

</script>

<style scoped>

h2 {
  display: inline-block;
}


.why-enter-active {
  animation: whyAnim 2s ease;
}


.why-leave-active {
  /* animation: whyLeaveAnim 2s ease; */
  animation: whyAnim 2s ease reverse;
}


@keyframes whyAnim {
  0% {
    transform: scale(0);
    opacity: 0;
  }

  50% {
    transform: scale(1.2);
    opacity: 0.5;
  }

  100% {
    transform: scale(1);
    opacity: 1;
  }
}

@keyframes whyLeaveAnim {
  0% {
    transform: translateX(0);
    opacity: 1;
  }

  100% {
    transform: translateX(-500px);
    opacity: 0;
  }
}

</style>

动画属性设置(一)

type属性不要乱用，少用甚至不用。

<template>
  <div class="app">
    <div>
      <button @click="isShow = !isShow">切换</button>
    </div>

    <transition name="why">
      <h2 v-if="isShow">
        要是有些事我没说，地坛，你别以为是我忘了，我什么也没忘，但是有些事只适合收藏。不能说，也不能想，却又不能忘。它们不能变成语言，它们无法变成语言，一旦变成语言就不再是它们了。它们是一片朦胧的温馨与寂寥，是一片成熟的希望与绝望，它们的领地只有两处：心与坟墓。比如说邮票，有些是用于寄信的，有些仅仅是为了收藏。
      </h2>
    </transition>
  </div>
</template>

<script setup>
import { ref } from 'vue';

const isShow = ref(false)

</script>

<style scoped>

h2 {
  display: inline-block;
}

/* transition */
.why-enter-from,
.why-leave-to {
  opacity: 0;
}

.why-enter-to,
.why-leave-from {
  opacity: 1;
}


.why-enter-active {
  animation: whyAnim 2s ease;
  transition: opacity 2s ease;
}

.why-leave-active {
  animation: whyAnim 2s ease reverse;
  transition: opacity 2s ease;
}


@keyframes whyAnim {
  0% {
    transform: scale(0);
  }

  50% {
    transform: scale(1.2);
  }

  100% {
    transform: scale(1);
  }
}

</style>

动画属性设置(二)

mode属性可以设置动画组件的播放顺序，一个动画结束了才会执行另外一个动画。

<template>
  <div class="app">
    <div>
      <button @click="isShow = !isShow">切换</button>
    </div>

    <!-- mode属性掌握 -->
    <transition name="why" mode="out-in">
      <h2 v-if="isShow">哈哈哈</h2>
      <h2 v-else>呵呵呵</h2>
    </transition>
  </div>
</template>

<script setup>
import { ref } from 'vue';

const isShow = ref(true)

</script>

<style scoped>

h2 {
  display: inline-block;
}

/* transition */
.why-enter-from,
.why-leave-to {
  opacity: 0;
}

.why-enter-to,
.why-leave-from {
  opacity: 1;
}


.why-enter-active {
  animation: whyAnim 2s ease;
  transition: opacity 2s ease;
}

.why-leave-active {
  animation: whyAnim 2s ease reverse;
  transition: opacity 2s ease;
}


@keyframes whyAnim {
  0% {
    transform: scale(0);
  }

  50% {
    transform: scale(1.2);
  }

  100% {
    transform: scale(1);
  }
}

</style>

动画组件动画

为两个组件的进入和退出制作动画

<template>
  <div class="app">
    <div>
      <button @click="isShow = !isShow">切换</button>
    </div>

    <!-- mode属性掌握 -->
    <transition name="why" mode="out-in" appear="">
      <component :is=" isShow ? 'home': 'about'"></component>
    </transition>
  </div>
</template>

<script>
import Home from './pages/Home.vue'
import About from './pages/About.vue'
export default {
  components: {
    Home,
    About
  }
}
</script>

<script setup>
import { ref } from 'vue';

const isShow = ref(true)

</script>

<style scoped>

h2 {
  display: inline-block;
}

/* transition */
.why-enter-from,
.why-leave-to {
  opacity: 0;
}

.why-enter-to,
.why-leave-from {
  opacity: 1;
}


.why-enter-active {
  animation: whyAnim 2s ease;
  transition: opacity 2s ease;
}

.why-leave-active {
  animation: whyAnim 2s ease reverse;
  transition: opacity 2s ease;
}


@keyframes whyAnim {
  0% {
    transform: scale(0);
  }

  50% {
    transform: scale(1.2);
  }

  100% {
    transform: scale(1);
  }
}

</style>

打乱序列的数组动画：

乱用underscore动画库来为数组的乱序制作动画，并且使用transition-group来包裹数组

<template>
  <div class="app">
    <button @click="addNumber">添加数字</button>
    <button @click="removeNumber">删除数字</button>
    <button @click="shuffleNumber">打乱数字</button>
    
    <transition-group tag="div" name="why">
      <template v-for="item in nums" :key="item">
        <span>{{ item }}</span>
      </template>
    </transition-group>
  </div>
</template>

<script setup>
import { reactive, ref } from 'vue';
import { shuffle } from "underscore";

const nums = ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])

const addNumber = () => {
  nums.value.splice(randomIndex(), 0, nums.value.length)
}

const removeNumber = () => {
  nums.value.splice(randomIndex(), 1)
}

const shuffleNumber = () => {
  nums.value = shuffle(nums.value)
}

const randomIndex = () => {
  return Math.floor(Math.random() * nums.value.length)
}

</script>

<style scoped>

span {
  margin-right: 10px;
  display: inline-block;
}

.why-enter-from,
.why-leave-to {
  opacity: 0;
  transform: translateY(30px);
}

.why-enter-to,
.why-leave-from {
  opacity: 1;
  transform: translateY(0);
}

.why-enter-active,
.why-leave-active {
  transition: all 2s ease;
}

.why-leave-active {
  position: absolute;
}


/* 针对其他移动的阶段需要的动画 */
.why-move {
  transition: all 2s ease;
}

</style>