视频讲解
Javascript最优雅的轮播~无缝轮播_哔哩哔哩_bilibili
源码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<title>无缝轮播</title>
<style>
* {
margin: 0;
padding: 0;
}
ul {
list-style: none;
}
#wrap {
overflow: hidden;
position: relative;
width: 1226px;
height: 580px;
margin: 200px auto 0;
}
#wrap .img-list {
display: flex;
position: relative;
left: 0px;
width: 100%;
height: 100%;
transition: 0.5s ease;
}
#wrap .img-list img {
width: 100%;
cursor: pointer;
}
#wrap a {
position: absolute;
top: 50%;
transform: translate(0, -50%);
display: block;
width: 40px;
height: 70px;
background-color: rgba(0, 0, 0, 0.7);
color: white;
user-select: none;
font-size: 30px;
text-align: center;
line-height: 70px;
text-decoration: none;
}
#wrap a.left {
left: 0;
}
#wrap a.right {
right: 0;
}
.circle-list {
display: flex;
position: absolute;
bottom: 20px;
left: 50%;
transform: translate(-50%, 0);
width: 240px;
height: 40px;
z-index: 8;
}
.circle-list > .circle {
margin: 0 5px;
width: 30px;
height: 30px;
background-color: #ecf0f1;
border-radius: 50%;
}
.circle-list > .circle.active {
background-color: #e74c3c;
}
</style>
</head>
<body>
<div id="wrap">
<!-- 图片列表 -->
<div class="img-list">
<img src="https://s1.ax1x.com/2020/09/26/0irm1P.jpg" />
<img src="https://s1.ax1x.com/2020/09/26/0irQ0g.jpg" />
<img src="https://s1.ax1x.com/2020/09/26/0ir8ts.jpg" />
<img src="https://s1.ax1x.com/2020/10/11/0gbKoV.jpg" />
<img src="https://s1.ax1x.com/2020/10/11/0gb7Os.jpg" />
</div>
<!-- 小箭头 -->
<div class="arrow">
<a href="javascript:;" class="left"><</a>
<a href="javascript:;" class="right">></a>
</div>
<!-- 小圆点 -->
<ul class="circle-list">
<li class="circle active" data-n="0"></li>
<li class="circle" data-n="1"></li>
<li class="circle" data-n="2"></li>
<li class="circle" data-n="3"></li>
<li class="circle" data-n="4"></li>
</ul>
</div>
<script>
// 获取左右按钮和图片列表
let oLeft = document.querySelector(".left");
let oRight = document.querySelector(".right");
let oImgList = document.querySelector(".img-list");
// 克隆第一张图片
let clonefirstImg = oImgList.firstElementChild.cloneNode();
// 将第一张图片添加至图片列表的末尾
oImgList.appendChild(clonefirstImg);
// 图片索引 代表当前是第几张图片 index:0代表第一张图片
let index = 0;
// 设置函数节流锁
let lock = true;
function handleRightBtn() {
if (!lock) return;
index++;
oImgList.style.left = index * -1226 + "px";
// 为什么要加过渡? 因为切换到了最后一张假图时会将过渡去掉
oImgList.style.transition = "0.5s ease";
if (index === 5) {
index = 0;
setTimeout(() => {
oImgList.style.left = 0;
// 取消过渡 500毫秒之后切换第一张
oImgList.style.transition = "none";
}, 500);
}
// 设置小圆点的高亮
setCircles();
// 关锁
lock = false;
setTimeout(() => {
lock = true;
}, 500);
}
// 右按钮的实现
oRight.addEventListener("click", handleRightBtn);
// 左按钮的实现 瞬间切换到假图然后拉到真实最后一张图片
oLeft.addEventListener("click", () => {
if (!lock) return;
index--;
if (index === -1) {
oImgList.style.left = 5 * -1226 + "px";
oImgList.style.transition = "none";
index = 4;
setTimeout(() => {
oImgList.style.left = index * -1226 + "px";
oImgList.style.transition = "0.5s ease";
}, 0);
} else {
oImgList.style.left = index * -1226 + "px";
}
// 设置小圆点的高亮
setCircles();
lock = false;
setTimeout(() => {
lock = true;
}, 500);
});
// 获取五个小圆点
const circles = document.querySelectorAll(".circle");
// 小圆点高亮的显示
function setCircles() {
for (let i = 0; i < circles.length; i++) {
if (i === index) {
circles[i].classList.add("active");
} else {
circles[i].classList.remove("active");
}
}
}
// 小圆点点击切换图片 使用事件代理
const oCircle = document.querySelector(".circle-list");
oCircle.addEventListener("click", (e) => {
// 当我点击小圆点的时候
if (e.target.nodeName.toLowerCase() === "li") {
// 当前元素的data-n对应得值 和index一一对应
const n = Number(e.target.getAttribute("data-n"));
index = n;
setCircles();
oImgList.style.transition = "0.5s ease";
oImgList.style.left = index * -1226 + "px";
}
});
// 自动轮播
let autoplay = setInterval(handleRightBtn, 2000);
const oWrap = document.getElementById("wrap");
// 移入停止轮播
oWrap.addEventListener("mouseenter", () => {
clearInterval(autoplay);
});
// 移出继续轮播
oWrap.addEventListener("mouseleave", () => {
// 设表先关
clearInterval(autoplay);
autoplay = setInterval(handleRightBtn, 2000);
});
// https://segmentfault.com/a/1190000018445196
</script>
</body>
</html>
