Vue <Transition> 组件

实例

使用内置的 <Transition> 组件在 <p> 元素被 v-if 移除时为其设置动画：

<Transition>
  <p v-if="exists">Hello World!</p>
</Transition>

定义与用法

内置的 <Transition> 组件用于在使用 v-if, v-show 或动态组件添加或删除元素时为其设置动画。

元素动画化的规则是在自动生成的类或 JavaScript 过渡钩子中编写的。请参阅下表。

在 <Transition> 组件的根级别上只能有一个元素。

Props

CSS Transition 过渡类

当我们使用 <Transition> 组件时，我们会自动获得 6 个不同的 CSS 类，当添加或删除元素时，我们可以使用它们来设置动画。

当添加（进入）或删除（离开）元素时，这些类在不同阶段处于活动状态:

JavaScript Transition 钩子

上面的过渡类对应于我们可以挂接以运行 JavaScript 代码的事件。

更多实例

实例 1

当 <p> 元素被切换时，它会滑入和滑出。

<template>
  <h1>Add/Remove <p> Tag</h1>
  <button @click="this.exists = !this.exists">{{btnText}}</button><br>
  <Transition>
    <p v-if="exists">Hello World!</p>
  </Transition>
</template>
<script>
export default {
  data() {
    return {
      exists: false
    }
  },
  computed: {
    btnText() {
      if(this.exists) {
        return 'Remove';
      }
      else {
        return 'Add';
      }
    }
  }
}
</script>
<style>
  .v-enter-from {
    opacity: 0;
    translate: -100px 0;
  }
  .v-enter-to {
    opacity: 1;
    translate: 0 0;
  }
  .v-leave-from {
    opacity: 1;
    translate: 0 0;
  }
  .v-leave-to {
    opacity: 0;
    translate: 100px 0;
  }
  p {
    background-color: lightgreen;
    display: inline-block;
    padding: 10px;
    transition: all 0.5s;
  }
</style>

实例 2

<p> 元素在进入和离开期间具有不同的背景色：

<template>
  <h1>Add/Remove <p> Tag</h1>
  <button @click="this.exists = !this.exists">{{btnText}}</button><br>
  <Transition>
    <p v-if="exists">Hello World!</p>
  </Transition>
</template>
<script>
export default {
  data() {
    return {
      exists: false
    }
  },
  computed: {
    btnText() {
      if(this.exists) {
        return 'Remove';
      }
      else {
        return 'Add';
      }
    }
  }
}
</script>
<style>
  .v-enter-active {
    background-color: lightgreen;
    animation: added 1s;
  }
  .v-leave-active {
    background-color: lightcoral;
    animation: added 1s reverse;
  }
  @keyframes added {
    from {
      opacity: 0;
      translate: -100px 0;
    }
    to {
      opacity: 1;
      translate: 0 0;
    }
  }
  p {
    display: inline-block;
    padding: 10px;
    border: dashed black 1px;
  }
</style>

实例 3

<p> 元素以不同的方式设置动画，使用命名 prop 来区分<Transition>组件。

<template>
  <h1>Add/Remove <p> Tag</h1>
  <p>The second transition in this example has the name prop "swirl", so that we can keep the transitions apart with different class names.</p>
  <hr>
  <button @click="this.p1Exists = !this.p1Exists">{{btn1Text}}</button><br>
  <Transition>
    <p v-if="p1Exists" id="p1">Hello World!</p>
  </Transition>
  <hr>
  <button @click="this.p2Exists = !this.p2Exists">{{btn2Text}}</button><br>
  <Transition name="swirl">
    <p v-if="p2Exists" id="p2">Hello World!</p>
  </Transition>
</template>
<script>
export default {
  data() {
    return {
      p1Exists: false,
      p2Exists: false
    }
  },
  computed: {
    btn1Text() {
      if(this.p1Exists) {
        return 'Remove';
      }
      else {
        return 'Add';
      }
    },
    btn2Text() {
      if(this.p2Exists) {
        return 'Remove';
      }
      else {
        return 'Add';
      }
    }
  }
}
</script>
<style>
  .v-enter-active {
    background-color: lightgreen;
    animation: added 1s;
  }
  .v-leave-active {
    background-color: lightcoral;
    animation: added 1s reverse;
  }
  @keyframes added {
    from {
      opacity: 0;
      translate: -100px 0;
    }
    to {
      opacity: 1;
      translate: 0 0;
    }
  }
  .swirl-enter-active {
    animation: swirlAdded 1s;
  }
  .swirl-leave-active {
    animation: swirlAdded 1s reverse;
  }
  @keyframes swirlAdded {
    from {
      opacity: 0;
      rotate: 0;
      scale: 0.1;
    }
    to {
      opacity: 1;
      rotate: 360deg;
      scale: 1;
    }
  }
  #p1, #p2 {
    display: inline-block;
    padding: 10px;
    border: dashed black 1px;
  }
  #p2 {
    background-color: lightcoral;
  }
</style>

实例 4

after-enter 事件触发要显示的 <div> 元素。

<template>
  <h1>JavaScript Transition Hooks</h1>
  <p>This code hooks into "after-enter" so that after the initial animation is done, a method runs that displays a red div.</p>
  <button @click="pVisible=true">Create p-tag!</button><br>
  <Transition @after-enter="onAfterEnter">
    <p v-show="pVisible" id="p1">Hello World!</p>
  </Transition>
  <br>
  <div v-show="divVisible">This appears after the "enter-active" phase of the transition.</div>
</template>
<script>
export default {
  data() {
    return {
      pVisible: false,
      divVisible: false
    }
  },
  methods: {
    onAfterEnter() {
      this.divVisible = true;
    }
  }
}
</script>
<style>
  .v-enter-active {
    animation: swirlAdded 1s;
  }
  @keyframes swirlAdded {
    from {
      opacity: 0;
      rotate: 0;
      scale: 0.1;
    }
    to {
      opacity: 1;
      rotate: 360deg;
      scale: 1;
    }
  }
  #p1, div {
    display: inline-block;
    padding: 10px;
    border: dashed black 1px;
  }
  #p1 {
    background-color: lightgreen;
  }
  div {
    background-color: lightcoral;
  }
</style>

实例 5

切换按钮触发 enter-cancelled 事件。

<template>
  <h1>The 'enter-cancelled' Event</h1>
  <p>Click the toggle button again before the enter animation is finished to trigger the 'enter-cancelled' event.</p>
  <button @click="pVisible=!pVisible">Toggle</button><br>
  <Transition @enter-cancelled="onEnterCancelled">
    <p v-if="pVisible" id="p1">Hello World!</p>
  </Transition>
  <br>
  <div v-if="divVisible">You interrupted the "enter-active" transition.</div>
</template>
<script>
export default {
  data() {
    return {
      pVisible: false,
      divVisible: false
    }
  },
  methods: {
    onEnterCancelled() {
      this.divVisible = true;
    }
  }
}
</script>
<style>
  .v-enter-active {
    animation: swirlAdded 2s;
  }
  @keyframes swirlAdded {
    from {
      opacity: 0;
      rotate: 0;
      scale: 0.1;
    }
    to {
      opacity: 1;
      rotate: 720deg;
      scale: 1;
    }
  }
  #p1, div {
    display: inline-block;
    padding: 10px;
    border: dashed black 1px;
  }
  #p1 {
    background-color: lightgreen;
  }
  div {
    background-color: lightcoral;
  }
</style>

实例 6

页面加载后，显示 prop 立即启动 <p> 元素动画。

<template>
  <h1>The 'appear' Prop</h1>
  <p>The 'appear' prop starts the animation when the p tag below is rendered for the first time as the page opens. Without the 'appear' prop, this example would have had no animation.</p>
  <Transition appear>
    <p id="p1">Hello World!</p>
  </Transition>
</template>
<style>
  .v-enter-active {
    animation: swirlAdded 1s;
  }
  @keyframes swirlAdded {
    from {
      opacity: 0;
      rotate: 0;
      scale: 0.1;
    }
    to {
      opacity: 1;
      rotate: 360deg;
      scale: 1;
    }
  }
  #p1 {
    display: inline-block;
    padding: 10px;
    border: dashed black 1px;
    background-color: lightgreen;
  }
</style>

实例 7

在动画处于 'enter' 和 'leave' 的情况下翻转图片。在删除旧图片之前会添加新图片。

<template>
  <h1>Transition Between Elements</h1>
  <p>Click the button to get a new image.</p>
  <p>The new image is added before the previous is removed. We will fix this in the next example with mode="out-in".</p>
  <button @click="newImg">Next image</button><br>
  <Transition>
    <img src="/img_pizza.svg" v-if="imgActive === 'pizza'">
    <img src="/img_apple.svg" v-else-if="imgActive === 'apple'">
    <img src="/img_cake.svg" v-else-if="imgActive === 'cake'">
    <img src="/img_fish.svg" v-else-if="imgActive === 'fish'">
    <img src="/img_rice.svg" v-else-if="imgActive === 'rice'">
  </Transition>
</template>
<script>
export default {
  data() {
    return {
      imgActive: 'pizza',
      imgs: ['pizza', 'apple', 'cake', 'fish', 'rice'],
      indexNbr: 0
    }
  },
  methods: {
    newImg() {
      this.indexNbr++;
      if(this.indexNbr >= this.imgs.length) {
        this.indexNbr = 0;
      }
      this.imgActive = this.imgs[this.indexNbr];
    }
  }
}
</script>
<style>
  .v-enter-active {
    animation: swirlAdded 1s;
  }
  .v-leave-active {
    animation: swirlAdded 1s reverse;
  }
  @keyframes swirlAdded {
    from {
      opacity: 0;
      rotate: 0;
      scale: 0.1;
    }
    to {
      opacity: 1;
      rotate: 360deg;
      scale: 1;
    }
  }
  img {
    width: 100px;
    margin: 20px;
  }
  img:hover {
    cursor: pointer;
  }
</style>

实例 8

在动画处于 'enter' 和 'leave' 的情况下翻转图片。mode="out-in" 阻止添加新图片，直到删除旧图片为止。

<template>
  <h1>mode="out-in"</h1>
  <p>Click the button to get a new image.</p>
  <p>With mode="out-in", the next image is not added until the current image is removed. Another difference from the previous example, is that here we use computed prop instead of a method.</p>
  <button @click="indexNbr++">Next image</button><br>
  <Transition mode="out-in">
    <img src="/img_pizza.svg" v-if="imgActive === 'pizza'">
    <img src="/img_apple.svg" v-else-if="imgActive === 'apple'">
    <img src="/img_cake.svg" v-else-if="imgActive === 'cake'">
    <img src="/img_fish.svg" v-else-if="imgActive === 'fish'">
    <img src="/img_rice.svg" v-else-if="imgActive === 'rice'">
  </Transition>
</template>
<script>
export default {
  data() {
    return {
      imgs: ['pizza', 'apple', 'cake', 'fish', 'rice'],
      indexNbr: 0
    }
  },
  computed: {
    imgActive() {
      if(this.indexNbr >= this.imgs.length) {
        this.indexNbr = 0;
      }
      return this.imgs[this.indexNbr];
    }
  }
}
</script>
<style>
  .v-enter-active {
    animation: swirlAdded 0.7s;
  }
  .v-leave-active {
    animation: swirlAdded 0.7s reverse;
  }
  @keyframes swirlAdded {
    from {
      opacity: 0;
      rotate: 0;
      scale: 0.1;
    }
    to {
      opacity: 1;
      rotate: 360deg;
      scale: 1;
    }
  }
  img {
    width: 100px;
    margin: 20px;
  }
  img:hover {
    cursor: pointer;
  }
</style>

实例 9

组件之间的切换设置动画。

<template>
  <h1>Transition with Dynamic Components</h1>
  <p>The Transition component wraps around the dynamic component so that the switching can be animated.</p>
  <button @click="toggleValue = !toggleValue">Switch component</button>
  <Transition mode="out-in">
    <component :is="activeComp"></component>
  </Transition>
</template>
<script>
  export default {
    data () {
      return {
        toggleValue: true
      }
    },
    computed: {
      activeComp() {
        if(this.toggleValue) {
          return 'comp-one'
        }
        else {
          return 'comp-two'
        }
      }
    }
  }
</script>
<style>
  .v-enter-active {
    animation: slideIn 0.5s;
  }
  @keyframes slideIn {
    from {
      translate: -200px 0;
      opacity: 0;
    }
    to {
      translate: 0 0;
      opacity: 1;
    }
  }
  .v-leave-active {
    animation: slideOut 0.5s;
  }
  @keyframes slideOut {
    from {
      translate: 0 0;
      opacity: 1;
    }
    to {
      translate: 200px 0;
      opacity: 0;
    }
  }
  #app {
    width: 350px;
    margin: 10px;
  }
  #app > div {
    border: solid black 2px;
    padding: 10px;
    margin-top: 10px;
  }
</style>

实例 10

组件之间的切换设置动画。

<template>
  <h1>The :css="false" Prop</h1>
  <p>With the 'css' prop set to 'false', we tell the compiler that JavaScript hooks are used instead of CSS transition classes.</p>
  <p>When we use :css="false", we must call done() inside the 'enter' and the 'leave' hooks, to tell the browser when those transitions are finished.</p>
  <button @click="pVisible=!pVisible">Toggle</button>
  <div>
    <Transition
      :css="false"
      @enter="onEnter"
      @after-enter="onAfterEnter"
      @before-leave="onBeforeLeave"
      @leave="onLeave"
    >
      <p
        v-if="pVisible"
        id="p1">
        Hello World!
      </p>
    </Transition>
  </div>
</template>
<script>
export default {
  data() {
    return {
      pVisible: false
    }
  },
  methods: {
    onEnter(el,done) {
      let pos = 0;
      window.requestAnimationFrame(frame);
      function frame() {
        if (pos > 150) {
          done();
        } else {
          pos++;
          el.style.left = pos + "px";
          window.requestAnimationFrame(frame);
        }
      }
    },
    onAfterEnter(el) {
      el.style.backgroundColor = "yellow";
    },
    onBeforeLeave(el) {
      el.style.backgroundColor = "lightgreen";
    },
    onLeave(el,done) {
      let pos = 150;
      window.requestAnimationFrame(frame);
      function frame() {
        if (pos < 0) {
          done();
        }
        else {
          pos--;
          el.style.left = pos + "px";
          window.requestAnimationFrame(frame);
        }
      }
    }
  }
}
</script>
<style>
  #p1 {
    position: absolute;
    padding: 10px;
    border: dashed black 1px;
    background-color: lightgreen;
  }
  #app > div {
    position: relative;
    background-color: coral;
    width: 300px;
    height: 300px;
    border: dashed black 1px;
    margin-top: 20px;
  }
</style>

实例 11

使用 enterActiveClass prop 将 'v-enter-active' CSS 类重命名为 'entering'。

<template>
  <h1>The 'enterActiveClass' Prop</h1>
  <button @click="this.exists = !this.exists">{{btnText}}</button><br>
  <Transition enter-active-class="entering">
    <p v-if="exists">Hello World!</p>
  </Transition>
</template>
<script>
export default {
  data() {
    return {
      exists: false
    }
  },
  computed: {
    btnText() {
      if(this.exists) {
        return 'Remove';
      }
      else {
        return 'Add';
      }
    }
  }
}
</script>
<style>
  .entering {
    background-color: lightgreen;
    animation: added 1s;
  }
  .v-leave-active {
    background-color: lightcoral;
    animation: added 1s reverse;
  }
  @keyframes added {
    from {
      opacity: 0;
      translate: -100px 0;
    }
    to {
      opacity: 1;
      translate: 0 0;
    }
  }
  p {
    display: inline-block;
    padding: 10px;
    border: dashed black 1px;
  }
</style>