轮播图的几种实现方式
2023-07-18 06:24
一、z-index透明度轮播
原理：将所有img元素重叠在一起，为想要展示的图片的z-index属性，设置为最大值。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
* {
margin: 0;
padding: 0;
}
div {
position: relative;
width: 500px;
height: 300px;
z-index: 10000;
}
div img {
position: absolute;
z-index: 10;
opacity: 0;
transition: all 0.5s ease;
}
div button {
width: 50px;
position: absolute;
z-index: 1000;
top: 150px;
cursor: pointer;
}
#btnLeft {
left: 0;
}
#btnRignt {
right: 0;
}
.active {
z-index: 1000;
opacity: 1;
}
ul {
position: absolute;
padding: 0;
list-style: none;
z-index: 1000;
right: 20px;
bottom: 20px;
cursor: pointer;
}
li {
float: left;
width: 8px;
height: 8px;
background-color: rgba(0, 0, 0, 0.4);
border-radius: 100%;
margin-right: 10px;
border: 2px solid black;
}
.liwhite {
background-color: white;
}
</style>
</head>
<body>
<div id="div">
<img src="./img/1.jpg" alt="" class="item active" />
<img src="./img/2.jpg" alt="" class="item" />
<img src="./img/3.jpg" alt="" class="item" />
<img src="./img/4.jpg" alt="" class="item" />
<img src="./img/5.jpg" alt="" class="item" />
<button id="btnLeft"><</button>
<button id="btnRignt">></button>
<ul>
<li class="liwhite" data-index="0"></li>
<li data-index="1"></li>
<li data-index="2"></li>
<li data-index="3"></li>
<li data-index="4"></li>
</ul>
</div>
<script>
var btnLeft = document.getElementById("btnLeft");
var btnRignt = document.getElementById("btnRignt");
var item = document.getElementsByClassName("item");
var li = document.getElementsByTagName("li");
var div = document.getElementById("div");
var index = 0;
//移除所有的active项
function removeClassActive() {
for (var i = 0; i < item.length; i++) {
item[i].className = "item";
li[i].className = "";
}
}
btnLeft.onclick = function () {
if (index <= 0) {
index = 5;
}
index--;
goindex();
};
function goindex() {
removeClassActive();
item[index].className = "item active";
li[index].className = "liwhite";
}
btnRignt.onclick = function () {
if (index >= 4) {
index = -1;
}
index++;
// console.log(li)
goindex();
};
function goindex1() {
if (index >= 4) {
index = -1;
} else if (index < 0) {
index = 4;
}
index++;
goindex();
}
//给每一个li挂上一个点击事件
for (var i = 0; i < li.length; i++) {
li[i].addEventListener("click", function () {
// console.log(this.li.indexOf())
var point = this.getAttribute("data-index");
index = point;
goindex();
});
}
// console.log(div)
var timer = setInterval(function () {
goindex1();
// 进入
div.onmouseenter = function () {
clearInterval(timer);
};
}, 1000);
// 移除
div.onmouseleave = function () {
clearInterval(timer);
timer = setInterval(function () {
goindex1();
}, 1000);
};
</script>
</body>
</html>
二、水平轮播
原理：将所有img元素放在一行，通过位移进行切换,通过overflow: hidden; 清除溢出部分
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
</head>
<style>
* {
margin: 0;
padding: 0;
}
div.content {
position: relative;
overflow: hidden;
width: 700px;
height: 400px;
border: 1px solid beige;
background-color: aqua;
}
ul {
position: absolute;
list-style: none;
}
ul.top > li {
float: left;
width: 700px;
height: 400px;
}
img {
width: 100%;
height: 100%;
}
button.perv {
position: absolute;
top: 191px;
left: 0;
}
button.next {
position: absolute;
top: 191px;
right: 0;
}
ul.bottom {
position: absolute;
top: 336px;
left: 20px;
}
ul.bottom > li {
float: left;
width: 25px;
height: 25px;
margin-left: 15px;
border: 1px solid #00ffff;
text-align: center;
line-height: 25px;
cursor: pointer;
}
.red {
background-color: red;
}
</style>
<script>
function $(n) {
return document.querySelector(n);
}
window.onload = function () {
var liIndex = 1;
var liWidth, liLenth, lilen, timer, timer2;
go();
function go() {
//复制前后li
var copy_li1 = $(".top>li:first-of-type").cloneNode(true);
$(".top").appendChild(copy_li1);
var copy_lilast = $(".top>li:nth-of-type(5)").cloneNode(true);
$(".top").insertBefore(copy_lilast, $(".top>li:first-of-type"));
//给ul宽度
liWidth = $(".top>li").clientWidth;
lilen = document.querySelectorAll(".top>li").length;
$(".top").style.width = lilen * liWidth + "px";
$(".top").style.left = -liWidth + "px";
//左右点击
$(".perv").onclick = function () {
prev(liIndex);
};
$(".next").onclick = function () {
next(liIndex);
};
//点击子弹
var bullets = document.querySelectorAll(".bottom>li");
for (var i = 0; i < bullets.length; i++) {
bullets[i].index = i;
bullets[i].onclick = function () {
liIndex = this.index + 1;
into(liIndex);
};
}
$(".content").onmouseenter = function () {
stop();
};
$(".content").onmouseleave = function () {
auto();
};
auto();
}
function prev() {
liIndex--;
into(liIndex);
}
function next() {
liIndex++;
into(liIndex);
}
function auto() {
clearInterval(timer2);
timer2 = setInterval(function () {
next();
}, 2000);
}
function stop() {
clearInterval(timer2);
}
function into(index) {
if (index == lilen) {
liIndex = index = 2;
$(".top").style.left = -liWidth + "px";
}
if (index == -1) {
liIndex = index = lilen - 3;
$(".top").style.left = -liWidth * (lilen - 2) + "px";
}
//
// 焦点映射
var foucindex;
var buttle = document.querySelectorAll(".bottom>li");
if (index == 0) {
foucindex = lilen - 3;
} else if (index == lilen - 1) {
foucindex = 0;
} else {
foucindex = index - 1;
}
$(".red").className = "";
buttle[foucindex].className = "red";
//作动画
var left = -index * liWidth;
clearInterval(timer);
timer = setInterval(function () {
var new_left = parseInt(getComputedStyle($(".top")).left);
var speed = (left - new_left) / 30;
speed = speed > 0 ? Math.ceil(speed) : Math.floor(speed);
$(".top").style.left = new_left + speed + "px";
}, 10);
console.log(liIndex);
}
};
</script>
<body>
<div class="content">
<ul class="top">
<li><img src="img/1.jpg" alt="" /></li>
<li><img src="img/2.jpg" alt="" /></li>
<li><img src="img/3.jpg" alt="" /></li>
<li><img src="img/4.jpg" alt="" /></li>
<li><img src="img/5.jpg" alt="" /></li>
</ul>
<button class="perv" type="button">perv</button>
<button class="next" type="button">next</button>
<ul class="bottom">
<li class="red">1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
</ul>
</div>
</body>
</html>