这篇文章主要讲解了“JavaScript如何实现无缝轮播图”，文中的讲解内容简单清晰，易于学习与理解，下面请大家跟着小编的思路慢慢深入，一起来研究和学习“JavaScript如何实现无缝轮播图”吧！
效果
一、实现过程
1）首先实现基本布局
<div class="carousel-container"> //图片列表 <div class="carousel-list"></div> //上一张 <div class="carousel-arrow carousel-arrow-left"><</div> //下一张 <div class="carousel-arrow carousel-arrow-right">></div> //导航点 <div class="indicator"> <span class="active"></span> <span></span> <span></span> </div> </div>2）主要样式
简单布局样式就不说了，主要讲如何将图片横向排列起来
先给容器设置相对定位，通过overflow将超出部分隐藏
.carousel-container { position: relative; width: 500px; height: 300px; background-color: #ccc; }然后图片列表设置相对定位和flex盒子，这样每一个滑块就横向排列成一排了
.carousel-container .carousel-list { position: relative; display: flex; height: 100%; width: 100%; }左右滑动按钮通过绝对定位+transform的方式移动到两边，导航点也是一样，就不一一详说了
二、如何实现无缝呢 （重点来了）
思路：
先实现向后滚动无缝连接，将最后一张复制一份放到最前面，当滚动到最后一张时，再次滚动，将要滚动到第一张时，先取消过渡transition，瞬间跳到最前面复制的那张上，然后继续运行动画到第一张，这样看起来就无缝了
向前滚动无缝连接，思路同上，复制第一张图片放到最后，当滚动到第一张，再次滚动时，瞬间跳到最后复制的那张图片上，继续滚动到轮播图的最后一张上。
主要代码
先获取到dom元素，currentIndex是当前轮播到的图片下标
let currentIndex = 0;const doms = { carouselList: document.querySelector('.carousel-list'), arrowLeft: document.querySelector('.carousel-arrow-left'), arrowRight: document.querySelector('.carousel-arrow-right'), indicator: document.querySelectorAll('.indicator span') }先初始化dom，复制图片
// 复制第一张放最后，最后一张图片放第一张之前 function init() { let lastImg = doms.carouselList.lastElementChild.cloneNode(true) let firstImg = doms.carouselList.firstElementChild.cloneNode(true) doms.carouselList.appendChild(firstImg) doms.carouselList.insertBefore(lastImg, doms.carouselList.firstElementChild) lastImg.style.position = 'absolute' lastImg.style.transform = 'translateX(-100%)' } //执行一下 init()实现到任意一张图片的方法
function moveTo(index) { doms.carouselList.style.transform = `translateX(-${index * 100}%)` doms.carouselList.style.transition = '.5s' // 去掉导航点选中效果 let active = document.querySelector('.indicator span.active') active.classList.remove('active') // 添加选中效果 doms.indicator[index].classList.add('active') currentIndex = index }给导航点绑定点击跳转事件
// 给导航点添加事件 doms.indicator.forEach((item, i) => { item.onclick = function () { moveTo(i); } })给前后按钮绑上执行事件,判断边界图片，及时取消过渡效果，瞬间跳到复制的图片位置，调用moveTo到第一张或最后一张图片上。
let indicatorLength = doms.indicator.length; function preSlide() { if (currentIndex === 0) { doms.carouselList.style.transition = 'none' doms.carouselList.style.transform = `translateX(-${indicatorLength * 100}%)` doms.carouselList.clientHeight moveTo(indicatorLength - 1) } else { moveTo(currentIndex - 1) } } function nextSlide() { if (currentIndex === doms.indicator.length - 1) { doms.carouselList.style.transition = 'none' doms.carouselList.style.transform = 'translateX(100%)' doms.carouselList.clientHeight moveTo(0) } else { moveTo(currentIndex + 1) } } doms.arrowLeft.onclick = function () { preSlide(); } doms.arrowRight.onclick = function () { nextSlide() }最后使用定时器调用nertSlide方法就实现自动播放了
function start(time = 2000) { setInterval(() => { nextSlide() }, time) } start()完整代码
<!DOCTYPE html><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"> <title>Document</title> <style> * { margin: 0; padding: 0; box-sizing: border-box; } .carousel-container { margin: 0 auto; position: relative; width: 500px; height: 300px; background-color: #ccc; } .carousel-container .carousel-list { position: relative; display: flex; height: 100%; width: 100%; } .carousel-container .carousel-list .slide { flex: 0 0 100%; height: 100%; width: 100%; } .slide a { display: flex; justify-content: center; align-items: center; height: 100%; width: 100%; } .slide a img { width: 100%; } .carousel-container .carousel-arrow { display: none; position: absolute; width: 36px; height: 36px; border-radius: 50%; color: white; text-align: center; line-height: 36px; cursor: pointer; background-color: rgba(31, 45, 61, .2); } .carousel-container:hover .carousel-arrow { display: block; } .carousel-container:hover .carousel-arrow:hover { background-color: rgba(31, 45, 61, .4); } .carousel-container .carousel-arrow-left { top: 50%; left: 2%; transform: translateY(-50%); } .carousel-container .carousel-arrow-right { top: 50%; right: 2%; transform: translateY(-50%); } .carousel-container .indicator { display: flex; position: absolute; left: 50%; top: 90%; transform: translateX(-50%) } .carousel-container .indicator span { margin: 2px 5px; padding: 3px; width: 5px; height: 5px; border: 1px solid white; border-radius: 5px; } .active { background-color: #fff; } </style></head><body> <div class="carousel-container"> <div class="carousel-list"> <div class="slide"> <a href=""> <img src="https://ts4.cn.mm.bing.net/th?id=OIP-C.kB-Ovasi0GW67-rmwnAcwAHaEo&w=316&h=197&c=8&rs=1&qlt=90&o=6&dpr=1.25&pid=3.1&rm=2"> </a> </div> <div class="slide"> <a href=""> <img src="https://ts1.cn.mm.bing.net/th?id=OIP-C.QPH1IBosDYBqaU3O6wV3YAHaEo&w=316&h=197&c=8&rs=1&qlt=90&o=6&dpr=1.25&pid=3.1&rm=2"></a> </div> <div class="slide"> <a href=""> <img src="https://ts2.cn.mm.bing.net/th?id=OIP-C.P3NSGTdAYdyqy5zJpb5QXQHaEo&w=316&h=197&c=8&rs=1&qlt=90&o=6&dpr=1.25&pid=3.1&rm=2" alt=""></a> </div> </div> <div class="carousel-arrow carousel-arrow-left"><</div> <div class="carousel-arrow carousel-arrow-right">></div> <div class="indicator"> <span class="active"></span> <span></span> <span></span> </div> </div></body><script> window.onload = function () { const doms = { carouselList: document.querySelector('.carousel-list'), arrowLeft: document.querySelector('.carousel-arrow-left'), arrowRight: document.querySelector('.carousel-arrow-right'), indicator: document.querySelectorAll('.indicator span') } let currentIndex = 0; function moveTo(index) { doms.carouselList.style.transform = `translateX(-${index * 100}%)` doms.carouselList.style.transition = '.5s' // 去掉导航点选中效果 let active = document.querySelector('.indicator span.active') active.classList.remove('active') // 添加选中效果 doms.indicator[index].classList.add('active') currentIndex = index } // 给导航点添加事件 doms.indicator.forEach((item, i) => { item.onclick = function () { moveTo(i); } }) // 复制第一张放最后，最后一张图片放第一张之前 function init() { let lastImg = doms.carouselList.lastElementChild.cloneNode(true) let firstImg = doms.carouselList.firstElementChild.cloneNode(true) doms.carouselList.appendChild(firstImg) doms.carouselList.insertBefore(lastImg, doms.carouselList.firstElementChild) lastImg.style.position = 'absolute' lastImg.style.transform = 'translateX(-100%)' } let indicatorLength = doms.indicator.length; function preSlide() { if (currentIndex === 0) { doms.carouselList.style.transition = 'none' doms.carouselList.style.transform = `translateX(-${indicatorLength * 100}%)` doms.carouselList.clientHeight moveTo(indicatorLength - 1) } else { moveTo(currentIndex - 1) } } function nextSlide() { if (currentIndex === doms.indicator.length - 1) { doms.carouselList.style.transition = 'none' doms.carouselList.style.transform = 'translateX(100%)' doms.carouselList.clientHeight moveTo(0) } else { moveTo(currentIndex + 1) } } doms.arrowLeft.onclick = function () { preSlide(); } doms.arrowRight.onclick = function () { nextSlide() } function start(time = 2000) { setInterval(() => { nextSlide() }, time) } start() init() }</script></html>感谢各位的阅读，以上就是“JavaScript如何实现无缝轮播图”的内容了，经过本文的学习后，相信大家对JavaScript如何实现无缝轮播图这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是编程网，小编将为大家推送更多相关知识点的文章，欢迎关注！
