複數元素/元件的漸變渲染 <transition-group>

#Vue3, #VueJS3, #transition

by ChrisWong

HTML

<script src="https://unpkg.com/vue@next"></script>
<div id="app">

  <button @click="add">Generates a random number</button>
  <button @click="list.length = 0">Remove all</button>

  <transition-group tag="ul" class="number-list" name="list">
    <li
      v-for="(item, index) in list"
      :key="index"
      class="item"
      @click="remove(index)"
    >
    {{ item }}
  </transition-group>
  
</div>

SCSS

#app {
  position: relative;
  display: block;
  padding: 1rem;
  font-size: 1rem;
}

button {
  font-size: 1rem;
  margin-bottom: 1rem;
  margin-right: 1rem;
}

.number-list {
  overflow: hidden;
  padding: 0;
  margin-bottom: 1.5rem;

  > li {
    display: block;
    float: left;
    width: 35px;
    height: 35px;
    text-align: center;
    line-height: 35px;
    background-color: #f00;
    color: #fff;
    margin-right: 1rem;
    margin-left: 0;
    margin-bottom: 1rem;
    cursor: pointer;
  }
}

.list-enter-active,
.list-leave-active,
.list-move {
  transition: opacity 0.7s, transform 0.7s;
}

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

.list-enter-from {
  opacity: 0;
  transform: translateY(-20px);
}

.list-leave-to {
  opacity: 0;
  transform: translateY(20px);
}

JavaScript

const app = Vue.createApp({
  data() {
    return {
      list: [1, 2, 3, 4, 5]
    }
  },
  methods: {
    add() {
      const randomNumber = Math.ceil(Math.random() * 100) + 1;
      this.list.push(randomNumber);
    },
    remove(index) {
      this.list.splice(index, 1);
    },
  }
});

app.mount('#app');