1.用户的显示和隐藏关闭
通过事件三部曲来
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
input{
color:#999;
}
</style>
</head>
<body>
<div class="box">
<input type="text" value="邮箱/ID/手机号">
</div>
<script>
var text=document.querySelector('input');
text.onfocus=function(){
this.value='';
text.style.color='#333';
this.style.borderColor='pink';
}
text.onblur=function(){
this.value='邮箱/ID/手机号';
this.style.color='#999';
}
</script>
</body>
</html>2.关闭广告
点击X时图片消失，改写X的内容
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
img{
position: absolute;
width: 200px;
height: 200px;
}
.bit{
position: relative;
left: 202px;
}
</style>
</head>
<body>
<img src="../images/yhx.jpg" alt="">
<i class="bit">X</i>
<script>
var img =document.querySelector('img');
var bit =document.querySelector('.bit');
bit.onclick = function(){
img.style.display='none';
bit.innerHTML='';
}
</script>
</body>
</html>3.新浪下拉菜单
先把第二个ul隐藏 display ：none ；然后再点击的时候display： block;
再次点击变为none;
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>下拉菜单</title>
<style>
*{
margin: 0%;
padding: 0%;
list-style: none;
}
.nav{
width: 400px;
margin: 100px auto;
}
.nav ul li{
float: left;
width: 100px;
height: 30px;
line-height: 30px;
text-align: center;
}
a{
text-decoration: none;
color: #fff;
display: block;
width: 100px;
height: 30px;
background-color: #ccc;
}
a.hover{
background: pink;
}
ul ul{
display: none;
}
</style>
</head>
<body>
<div class="nav">
<ul>
<li class="li1"><a href="#">微博</a></li>
<ul class="ul1">
<li ><a href="#">私信</a></li>
<li ><a href="#">评论</a></li>
<li ><a href="#">@我</a></li>
</ul>
</ul>
</div>
<script>
var myli1=document.querySelector('.li1');
var myul1=document.querySelector('.ul1');
myli1.onmouseover =function(){
myul1.style.display='block';
}
myli1.onmouseout =function(){
myul1.style.display='none';
}
</script>
</body>
</html>3.1 通过父子结点来设计下拉菜单
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width= , initial-scale=1.0">
<title>Document</title>
<style>
*{
margin: 0;
padding: 0;
}
.box{
text-align: center;
overflow: hidden;
margin-top: 100px;
margin-left: 600px;
}
a{
text-decoration: none;
color: #000;
}
ul{
list-style: none;
}
.box>li{
float: left;
list-style: none;
padding: 10px;
}
.box>li>a:hover{
background-color: #eee;
}
.box ul{
display: none;
line-height: 20px;
border-left: 1px solid #fecc5b;
border-right: 1px solid #fecc5b;
}
.box ul li{
border-bottom: 1px solid #fecc5b;
}
.box ul li:hover{
background-color: yellow;
}
</style>
</head>
<body>
<div class="box">
<li><a href="#">微博</a>
<ul>
<li><a href="#">私信</a></li>
<li><a href="#">评论</a></li>
<li><a href="#">@我</a></li>
</ul>
</li>
<li><a href="#">微博</a>
<ul>
<li><a href="#">私信</a></li>
<li><a href="#">评论</a></li>
<li><a href="#">@我</a></li>
</ul>
</li>
<li><a href="#">微博</a>
<ul>
<li><a href="#">私信</a></li>
<li><a href="#">评论</a></li>
<li><a href="#">@我</a></li>
</ul>
</li>
</div>
<script>
var box = document.querySelector('.box');
var lis = box.children;
for(var i=0;i<lis.length;i++){
lis[i].onmouseover=function(){
this.children[1].style.display='block';
}
lis[i].onmouseout=function(){
this.children[1].style.display='none';
}
}
</script>
</body>
</html>4.开关灯
知道body整个身体部分调用以及颜色的更改 document.body.style.backgroundColor
关键点。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<button id="kgd">开灯</button>
<script>
var box=document.querySelector('box');
var input=document.body;
kgd.onclick=function(){
if(this.innerHTML=='开灯'){
this.innerHTML='关灯';
document.body.style.backgroundColor='black';
}
else{
this.innerHTML='关灯';
document.body.style.backgroundColor='#fff';
}
}
</script>
</body>
</html>