布局：
div.slider > ul + div.arrow
ul > ll（*8）> a > img
div.arrow > span.arrow-left + span.arrow-right
案例分析：
当左箭头一点击，上一张图片渐渐的显示，其他图片渐渐的隐藏
当右箭头一点击，下一张图片渐渐的显示，其他图片渐渐的隐藏
关键代码
$(function(){
var count=0;
$(".arrow-left").click(function(){
count--;
if(count<0)
{
count=7;
}
$(.slider li).eq(count)。fadeIn().siblings().fadeOut();
})
$(".arrow-right").click(function(){
count++;
if(count > 7)
{
count=0;
}
$(".slider li").eq(count).fadeIn().siblings().fadeOut();
})
})
完整代码
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<title>京东商城</title>
<style>
* {
margin: 0;
padding: 0;
list-style: none;
}
.slider {
height: 340px;
width: 790px;
margin: 100px auto;
position: relative;
}
.slider li {
position: absolute;
display: none;
}
.slider li:first-child {
display: block;
}
.arrow {
display: none;
}
.slider:hover .arrow {
display: block;
}
.arrow-left,
.arrow-right {
font-family: "SimSun", "宋体";
width: 30px;
height: 60px;
background-color: rgba(0, 0, 0, 0.1);
position: absolute;
top: 50%;
margin-top: -30px;
cursor: pointer;
text-align: center;
line-height: 60px;
color: #fff;
font-weight: 700;
font-size: 30px;
}
.arrow-left:hover,
.arrow-right:hover {
background-color: rgba(0, 0, 0, .5);
}
.arrow-left {
left: 0;
}
.arrow-right {
right: 0;
}
</style>
</head>
<body>
<div class="slider">
<ul>
<li><a href="#"><img src="images/1.jpg" alt=""></a></li>
<li><a href="#"><img src="images/2.jpg" alt=""></a></li>
<li><a href="#"><img src="images/3.jpg" alt=""></a></li>
<li><a href="#"><img src="images/4.jpg" alt=""></a></li>
<li><a href="#"><img src="images/5.jpg" alt=""></a></li>
<li><a href="#"><img src="images/6.jpg" alt=""></a></li>
<li><a href="#"><img src="images/7.jpg" alt=""></a></li>
<li><a href="#"><img src="images/8.jpg" alt=""></a></li>
</ul>
<!--箭头-->
<div class="arrow">
<span class="arrow-left"><</span>
<span class="arrow-right">></span>
</div>
</div>
<script src="jquery-1.12.4.js"></script>
<script>
$(function () {
var count = 0;
$(".arrow-right").click(function () {
count++;
//if(count == $(".slider li").length){
if (count>7) {
count = 0;
}
console.log(count);
//让count渐渐的显示，其他兄弟渐渐的隐藏
$(".slider li").eq(count).fadeIn().siblings().fadeOut();
});
$(".arrow-left").click(function () {
count--;
//if(count == -1){
if (count<0) {
//count = $(".slider li").length - 1;
count=7;
}
console.log(count);
//让count渐渐的显示，其他兄弟渐渐的隐藏
$(".slider li").eq(count).fadeIn().siblings().fadeOut();
})
});
</script>
</body>
</html>