效果：
轮播图在向一个方向移动的同时，要对其每一个图片的大小，位置，透明度以及层级进行改变
原理：
轮播图向左移动时将第一个子元素剪切到末尾，轮播图向右移动时，将末尾子元素剪切到最前面，以此实现无缝轮播效果，再因为li剪切后，下一个li会补上（例如第一个子元素被剪切到最后时，第二个字元素会补上成为第一个子元素），所以li下标不变，以次来修改每一个位置的li的属性（大小，位置，透明度，层级）
HTML代码：
<body>
<div class="smallBox">
<div class="arrowLeft">←</div>
<div class="smallPicBox"> //用一个div存放一个ul，并对ul里的每一个li进行初始样式设置
<ul>
<li id="li1" style="position: absolute;top:calc(50% - 200px);left: 0px;z-index:1;background-color: aqua;transform: scale(0.5);transition: 0.3s;opacity: 0.5;background-image: url(./images/01.jpg);background-size: cover;"></li>
<li id="li2" style="position: absolute;top:calc(50% - 200px);left: 150px; z-index:2;background-color: red;transform: scale(0.7); transition: 0.3s;opacity: 0.7;background-image: url(./images/02.jpg);background-size: cover;"></li>
<li id="li3" style="position: absolute;top:calc(50% - 200px);left: 300px; z-index:3;background-color: blue;transform: scale(0.9); transition: 0.3s;opacity: 0.9;background-image: url(./images/03.jpg);background-size: cover;"></li>
<li id="li4" style="position: absolute;top:calc(50% - 200px);left: 450px; z-index:4;background-color: green;transform: scale(1); transition: 0.3s;opacity: 1;background-image: url(./images/04.jpg);background-size: cover;"></li>
<li id="li5" style="position: absolute;top:calc(50% - 200px);left: 600px; z-index:3;background-color: yellow;transform: scale(0.9); transition: 0.3s;opacity: 0.9;background-image: url(./images/05.jpg);background-size: cover;"></li>
<li id="li6" style="position: absolute;top:calc(50% - 200px);left: 750px; z-index:2;background-color: gray;transform: scale(0.7); transition: 0.3s;opacity: 0.7;background-image: url(./images/06.jpg);background-size: cover;"></li>
<li id="li7" style="position: absolute;top:calc(50% - 200px);left: 900px; z-index:1;background-color: deeppink;transform: scale(0.5); transition: 0.3s;opacity: 0.5;background-image: url(./images/07.jpg);background-size: cover;"></li>
</ul>
</div>
<div class="arrowRight">→</div>
</div>
</div>
</body>
CSS代码：
<style>
*{
margin: 0;
padding: 0;
list-style: none;
}
.albumBox{
width: 1200px;
height: 400px;
margin: 0 auto;
border: 1px solid #000;
}
.smallBox{
height: 400px;
line-height: 400px;
position: relative;
}
.smallPicBox{
width: 1100px;
height: 400px;
float: left;
position: relative;
}
.smallPicBox ul{
width: 100%;
height: 400px;
}
.smallPicBox li{
width: 320px;
height: 400px;
float: left;
border: 1px solid #000;
box-sizing: border-box;
}
.smallBox .current::after{
content: "\25b2";
position: absolute;
top: -31px;
left: 70px;
color: red;
}
.arrowLeft{
width: 50px;
height: 400px;
position: absolute;
left: 0;
border: 1px solid #000;
box-sizing: border-box;
background-color: gray;
z-index: 10;
}
.arrowRight{
width: 50px;
height: 400px;
position: absolute;
right: 0;
border: 1px solid #000;
box-sizing: border-box;
background-color: gray;
z-index: 10;
}
</style>
JS代码：
<script>
var arrowLeft=document.querySelector(".arrowLeft")
var arrowRight=document.querySelector(".arrowRight")
var ul=document.querySelector(".smallPicBox ul")
var li=document.querySelectorAll(".smallPicBox li")
var timerId=0
arrowLeft.onclick=function(){ //左箭头点击事件
li=document.getElementsByTagName('li')
ul.appendChild(li[0]) //将ul的第0个子元素剪切到末尾，实现无缝轮播
posi(li) //修改每一个li的属性
}
arrowRight.onclick=function(){ //右箭头点击事件
li=document.getElementsByTagName('li') //重新获取li
ul.insertBefore(li[6],li[0]) //将ul的最后一个子元素剪切到最前面，实现无缝轮播
posi(li) //修改每一个li的属性
}
function posi(li){ //修改li属性函数
var n1=0
for(var x=0;x<li.length;x++){ //修改位置
li[x].style.left=n1+'px'
n1=n1+150
}
for(var i=0;i<li.length/2;i++){ //修改层级
li[i].style.zIndex=i+1
li[li.length-1-i].style.zIndex=i+1
}
li[3].style.zIndex='4'
var n2=0.3
for(var j=0;j<li.length/2;j++){ //缩放
n2=parseFloat(n2+0.2)
li[j].style.transform='scale('+n2+')'
li[li.length-1-j].style.transform='scale('+n2+')'
}
li[3].style.transform='scale(1)'
var n3=0.3
for(var k=0;k<li.length/2;k++){ //修改透明度
n3=parseFloat(n3+0.2)
li[k].style.opacity=n3
li[li.length-1-k].style.opacity=n3
}
li[3].style.opacity='1'
}
//鼠标移入移出
temerId=setInterval(function(){
arrowLeft.click()
}, 1000);
arrowLeft.onmouseover=function(){
clearInterval(temerId)
}
arrowLeft.onmouseout=function(){
temerId=setInterval(function(){
arrowLeft.click()
}, 1000);
}
arrowRight.onmouseover=function(){
clearInterval(temerId)
}
arrowRight.onmouseout=function(){
temerId=setInterval(function(){
arrowLeft.click()
}, 1000);
}
</script>
注：本例js是直接写在body里的，也可以单独写一个js文件，在引入到html界面
效果图：
