用vue寫一個仿簡書的輪播圖

原文地址：用vue寫一個仿簡書的輪播圖
先展示最終效果：

Vue的理念是以數據驅動視圖，所以拒絕通過改變元素的margin-top來實現滾動效果。寫好css樣式，只需改變每張圖片的class即可實現輪播效果。可以將輪播圖看成兩個，如圖所示：

寫好每個class的樣式：

$width: 800px;      // 容器寬度
$height: 300px;     // 容器高度
$bWidth: 500px;     // 大圖片寬度
$sWidth: $width - $bWidth;  // 小圖片寬度
$sHeight: $height / 2;  // 小圖片高度
#slider-wrapper{
    width: $width;
    height: $height;
    margin: 0 auto;
    cursor: pointer;
    background: #ddd;
    border-radius: 5px;
    box-shadow: 0 1px 6px rgba(0,0,0,0.117647), 0 1px 4px rgba(0,0,0,0.117647);
    display: flex;
    overflow: hidden;
    div{
        display: inline-block;
    }
}
.main-slide{
    width: $bWidth;
    height: $height;
    float: left;
    transition: all .4s ease;
}
.extra-slide{
    width: $sWidth;
    position: relative;
    .extra-slide-item{
        position: absolute;
        width: $sWidth;
        height: $sHeight;
        left: 0;
        transition: .4s ease-out;
    }
    .extra-slide-top{
        top: -$sHeight;
    }
    .extra-slide-middle-first{
        top: 0;
        z-index: 2
    }
    .extra-slide-middle-second{
        top: $sHeight;
        z-index: 2
    }
    .extra-slide-bottom{
        top: $height
    }
    .extra-slide-hide{
        display: none!important;
    }
}

模板包含兩個輪播圖：

<div id="slider-wrapper" @mouseover="stop" @mouseout="start">
    <div class="main-slide" :style="`background: url(${slideConfig[nowIndex].src})`"></div>
    <div class="extra-slide">
        <div class="extra-slide-item" :class="slideClass(i)" v-for="(v, i) in slideConfig" :key="i" :style="`background: url(${v.src}); background-size: cover`"></div>
    </div>
</div>

scripts部分，設置一個nowIndex，定時改變nowIndex。所有圖片的class根據這個nowIndex來變化：

import slideConfig from './slideConfig'
const slideLength = slideConfig.length
export default {
    name: 'slider',
    data: function() {	
        return {
            slideConfig: slideConfig,
            slideInterval: null,
            nowIndex: 0
        }
    },
    methods: {
        resetIndex(i) {
            return i > slideLength - 1 ? i - slideLength : i
        },
        slideClass(i) {
            let nowIndex = this.nowIndex
            let map = new Map([
                [this.resetIndex(nowIndex), 'extra-slide-top'],
                [this.resetIndex(nowIndex + 1), 'extra-slide-middle-first'],
                [this.resetIndex(nowIndex + 2), 'extra-slide-middle-second'],
                [this.resetIndex(nowIndex + 3), 'extra-slide-bottom']
            ])
            return map.get(i) ? map.get(i) : 'extra-slide-hide'
        },
        start() {
            this.slideInterval = setInterval(() => {
                this.nowIndex = this.nowIndex > slideLength - 2 ? 0 : this.nowIndex + 1
                console.log(this.nowIndex)
            }, 2000)
        },
        stop() {
            clearInterval(this.slideInterval)
            this.slideInterval = null
        }
    },
    mounted() {
        this.start()
    },
    destroyed() {
        this.stop()
    }
}

slideConfig，這里可以寫成組件的props：

const prefix = '/src/assets/'
const slideConfig = [{
  src: prefix + 's1.jpg',
  title: '圖1',
  desc: '說明1'
}, {
  src: prefix + 's2.jpg',
  title: '圖2',
  desc: '說明2'
}, {
  src: prefix + 's3.jpg',
  title: '圖3',
  desc: '說明3'
}, {
  src: prefix + 's4.jpg',
  title: '圖4',
  desc: '說明4'
}, {
  src: prefix + 's5.jpg',
  title: '圖5',
  desc: '說明5'
}, {
  src: prefix + 's6.jpg',
  title: '圖6',
  desc: '說明6'
}]
export default slideConfig

gitHub傳送門：https://github.com/bougieL/jianshuslider