一、获取滚动值案例
实例
<!DOCTYPE html>
<html>
<head>
<title>获取滚动值案例</title>
<link rel="icon" type="image/x-icon" href="images/2.png">
<script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
<style type="text/css">
*{margin: 0;padding: 0;}
.content{ width:100%;height:60px;
background: rgba(160,3,162,0.1);
box-shadow: 1px 3px 7px #ccc;
line-height: 60px;
position: fixed;
}
.content_2{ background: rgba(160,3,162,0.4);}
form{width: 500px;height: 35px;position: relative;margin: 0 auto;}
input{width:480px;height: 35px;border-radius: 20px;border:none;outline: none;padding-left:20px;}
button{width: 70px;height:35px;order:none;
border-top-right-radius: 20px;border-bottom-right-radius: 20px;border: none;
color: #fff;position: absolute;right:0;top:14px;
outline: none;font-weight: bold;
background: rgba(160,3,162,0.4);
}
[placeholder]{color:rgba(160,3,162,0.6)}
.pic{width: 70%;height: 580px;background: url(images/3.jpg);margin: 0 auto;}
.box{width: 70%;height:1200px;background:rgba(108,108,106,0.1);margin: 0 auto; }
</style>
</head>
<body>
<!-- 顶部导航 -->
<div class="content">
<form>
<input type="text" placeholder="# 请输入关键词 #">
<button>全网搜</button>
</form>
</div>
<!-- 轮播图 -->
<div class="pic"></div>
<!-- 页面详情 -->
<div class="box"></div>
<script>
$(function(){
$(window).scroll(function(){
//判断滚动条距离顶部距离，如大于导航栏高度则隐藏
if($(window).scrollTop()>60){
$('.content').css('display','none')
}else{
$('.content').css('display','block')
}
//判断滚动条距离顶部距离，如大于轮播图高度则显示
if($(window).scrollTop()>580){
$('.content').addClass('content_2').css('display','block')
}else{
$('.content').removeClass('content_2')
}
})
})
</script>
</body>
</html>运行实例 »
点击 "运行实例" 按钮查看在线实例
二、点击商品选中效果
*自己做了这个案例，点击加入购物车按钮不弹窗，并且打印form列表只有 num=1 ，其他属性不打印，检查多次未发现代码问题，麻烦老师指点下。
实例
<!DOCTYPE HTML>
<html>
<head>
<title>点击商品选中效果</title>
<meta charset="utf-8"/>
<link rel="icon" type="image/x-icon" href="images/2.png">
<script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
<style type="text/css">
* {margin: 0px auto;padding: 0px;}
.top {width: 402px;height: 35px;
line-height: 35px;text-align:center;
margin-top: 50px;
background: #C40000;color:#fff;
}
.main {width: 400px;height: 400px;border: 1px solid #C40000;}
p {width: 400px;height: 26px;margin-top:10px;}
b {width: 90px;height: 26px;
line-height: 26px;text-align: center;
font-size: 12px;color:#838383;
border: 1px solid #ccc;
float: left;margin-left: 5px;}
span {width: 90px;height: 26px;line-height: 26px;
text-align: center;font-size: 12px;
color:#838383;border: 1px solid #ccc;
display: block;float: left;margin-left: 5px;}
span:hover {cursor: pointer;}
button {width: 120px;height: 35px;background: #C40000;color: white;border: 0px;}
button:hover {cursor: pointer;}
.notice{
border:0px;
}
.select{
border:2px solid #C40000;
width: 88px;
height: 24px;
line-height: 24px;
color: red;
}
</style>
</head>
<body>
<div class="top">请选择信息后加入购物车</div>
<div class="main">
<p class="item" name="version">
<b class="notice">版本</b>
<span>ONE A2001</span>
<span>ONE A0001</span>
<span>ONE A1001</span>
</p>
<p class="item" name="color">
<b class="notice">机身颜色</b>
<span>白色</span>
<span>黑色</span>
<span>金色</span>
</p>
<p class="item" name="type">
<b class="notice">套餐类型</b>
<span>标配</span>
<span>套餐一</span>
<span>套餐二</span>
</p>
<p class="item" name="ram">
<b class="notice">运行内存</b>
<span>2GB</span>
<span>3GB</span>
<span>4GB</span>
</p>
<p class="item" name="rom">
<b class="notice">机身内存</b>
<span>16GB</span>
<span>32GB</span>
<span>64GB</span>
</p>
<p class="item" name="location">
<b class="notice">产地</b>
<span>中国大陆</span>
<span>港澳台</span>
</p>
<p class="item" name="price">
<b class="notice">价格</b>
<span>999元抢购</span>
</p>
<p class="item1" name="num">
<b class="notice">数量</b>
<input type="number" value="1" style="width:40px;height:26px;">
</p>
<p style="margin-top:30px;margin-left:95px;">
<button class="bu1" id='sub'>加入购物车</button>
</p>
</div>
<script type="text/javascript">
$(function() {
$('span').click(function(){
if($(this).hasClass('select')){// 匹配span中是否带有class为select
$(this).removeClass('select')//含有就清除
}else{
// 没有就添加上select的class名，同时匹配同级span，清除同级其他span中的选中样式
$(this).addClass('select').siblings('span').removeClass('select')
}
})
$('#sub').click(function(){
//建立一个对象，储存信息
let form={}
//方便用于判断
let flag=true
//each() 方法规定为每个匹配元素规定运行的函数
// 判断是否每个选项都选中; 没选中则弹窗警告; 选中了则添加至需要发送的表单数据里面
$('.item').each(function(){
if($(this).children('span.select').lenght!=1){
flag=false
}else{
let key=$(this).attr('name')
let value=$(this).children('span.select').html()
form[key]=value//将键值对一一对应
}
})
//判断***数量是否小于0
if($('.item1 input').val()<=0){
flag=false
alert('***数量不能小于1')
}else{
form['num']=$('.item1 input').val()
console.log(form)
}
if(flag){
alert('可以加入购物车了')
}
})
});
</script>
</body>
</html>运行实例 »
点击 "运行实例" 按钮查看在线实例
总结：今天学习了addClass\removeClass\hasClass方法添加删除，查找class的方法