1. 前言

快要雙十一了，然后公司要制作一個展示的電子大屏，其中總金額的數(shù)字需要滾動的切換效果，類似于這樣:

動畫.gif

2. 思考&實現(xiàn)

2.1 思考

誒，作為十年代碼經(jīng)驗常年摸魚的我，想起來vue中的transition-group可以實現(xiàn)類似的效果,首先來看看官網(wǎng)的案例^[1]效果:

2.gif

2.2 實現(xiàn)

于是我們先參照官網(wǎng)實現(xiàn)一個簡單的效果:

3.gif

由于項目比較簡單，所以這里采用的是cdn方式，代碼如下:


<html lang="en">
<head>    <meta charset="UTF-8">    <meta http-equiv="X-UA-Compatible" content="IE=edge">    <meta name="viewport" content="width=device-width, initial-scale=1.0">    <style>        * {            margin: 0px;            padding: 0px;        }
        body,        html {            min-width: 1920px;            min-height: 1080px;            width: 100%;            height: 100%;        }
        #app {            position: relative;        }
        .amount {            color: gold;            font-size: 85px;            display: flex;            justify-content: center;        }
        .list-enter-active,        .list-leave-active {            transition: transform 1s ease, opacity 1s ease;        }
        .list-enter-from {            opacity: 0;            transform: translateY(50%);        }
        .list-leave-to {            opacity: 0;            transform: translateY(-50%);        }style>
    <title>Documenttitle>head>
<body id="app">    <div class="amount">        <div style="display: flex;">            <span>￥span>            <transition-group name="list" tag="p">                <p style="display: inline-block;" v-for="(item , index) in todayAmountComputed" :key="item + index">                    {{item}}p>            transition-group>        div>    div>body>
<script src="https://unpkg.com/vue@next" defer>script>
<script>    document.addEventListener('DOMContentLoaded', () => {        Vue.createApp({            data() {                return {                    todayAmount: '0',                    platformSales1: 4090013,                }            },            computed: {                todayAmountComputed() {                    return this.todayAmount.split('');                },            },            mounted() {                setInterval(() => {                    if (this.todayAmount === '0') {                        this.todayAmount = '1000';                    }                    this.todayAmount = '' + Math.floor(Math.random() * 10000);                }, 2000);            },        }).mount('#app');    })script>
html>
復(fù)制代碼

現(xiàn)在離完整的效果，其實只差一步了，現(xiàn)在由于原來的數(shù)字會占用空間，所以導(dǎo)致離開的和進(jìn)入的沒有在同一直線上，所以，我們加上position:absoulte,再使用left定位將它們固定在合理的位置上,代碼如下:


"app">
????<div?id="amount">
????????<div?style="display:?flex;">
????????????<span>￥span>
????????????<transition-group?name="list"?tag="p"?style="position:?relative;">
????????????????<p?style="display:?inline-block;position:?absolute;"?v-for="(item?,?index)?????????????????????in?todayAmountComputed"
????????????????????:style="{
????????????????????left:??index?*?50?+?'px',
????????????????????}"?:key="item?+?index">
????????????????????{{item}}p>
????????????transition-group>
????????div>
????div>
</body>

復(fù)制代碼

此時就會呈現(xiàn)出下列效果:

4.gif

哇咔咔，很接近了，有木有。

3. 注入靈魂

嘿嘿嘿，最后就是注入靈魂,給每個數(shù)字添加一點點延遲:

"app">
????<div?id="amount">
????????<div?style="display:?flex;">
????????????<span>￥span>
????????????<transition-group?name="list"?tag="p"?style="position:?relative;">
????????????????<p?style="display:?inline-block;position:?absolute;"?v-for="(item?,?index)?????????????????????in?todayAmountComputed"
????????????????????:style="{
????????????????????left:??index?*?50?+?'px',
????????????????????'transition-delay':?0.1?*?index?+?'s'
????????????????????}"?:key="item?+?index">
????????????????????{{item}}p>
????????????transition-group>
????????div>
????div>
</body>
復(fù)制代碼

最終效果如下:

5.gif

最后附上最終代碼鏈接參考^[2]:

4. 總結(jié)

鏈接：

[1]https://v3.cn.vuejs.org/guide/transitions-list.html

[2]https://gitee.com/Agrement/javascript/blob/master/%E6%8E%98%E9%87%91/index.html

花10分鐘用Vue 實現(xiàn) 1 個數(shù)字滾動效果