DOM相关知识
一、查找元素
间接查找
parentNode // 父节点
childNodes // 所有子节点
firstChild // 第一个子节点
lastChild // 最后一个子节点
nextSibling // 下一个兄弟节点
previousSibling // 上一个兄弟节点 parentElement // 父节点标签元素
children // 所有子标签
firstElementChild // 第一个子标签元素
lastElementChild // 最后一个子标签元素
nextElementtSibling // 下一个兄弟标签元素
previousElementSibling // 上一个兄弟标签元素
二、操作
1、内容
innerText 文本
outerText
innerHTML HTML内容
innerHTML
value 值
2、属性
attributes // 获取所有标签属性
setAttribute(key,value) // 设置标签属性
getAttribute(key) // 获取指定标签属性 /*
var atr = document.createAttribute("class");
atr.nodeValue="democlass";
document.getElementById('n1').setAttributeNode(atr);
*/
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body>
<input type="button" value="全选" onclick="CheckAll();"/>
<input type="button" value="取消" onclick="CancelAll();"/>
<input type="button" value="反选" onclick="ReverseCheck();"/> <table border="1" >
<thead> </thead>
<tbody id="tb">
<tr>
<td><input type="checkbox" /></td>
<td>111</td>
<td>222</td>
</tr>
<tr>
<td><input type="checkbox" /></td>
<td>111</td>
<td>222</td>
</tr>
<tr>
<td><input type="checkbox" /></td>
<td>111</td>
<td>222</td>
</tr>
<tr>
<td><input type="checkbox" /></td>
<td>111</td>
<td>222</td>
</tr>
</tbody>
</table>
<script>
function CheckAll(ths){
var tb = document.getElementById('tb');
var trs = tb.childNodes;
for(var i =0; i<trs.length; i++){ var current_tr = trs[i];
if(current_tr.nodeType==1){
var inp = current_tr.firstElementChild.getElementsByTagName('input')[0];
inp.checked = true;
}
}
} function CancelAll(ths){
var tb = document.getElementById('tb');
var trs = tb.childNodes;
for(var i =0; i<trs.length; i++){ var current_tr = trs[i];
if(current_tr.nodeType==1){
var inp = current_tr.firstElementChild.getElementsByTagName('input')[0];
inp.checked = false;
}
}
} function ReverseCheck(ths){
var tb = document.getElementById('tb');
var trs = tb.childNodes;
for(var i =0; i<trs.length; i++){
var current_tr = trs[i];
if(current_tr.nodeType==1){
var inp = current_tr.firstElementChild.getElementsByTagName('input')[0];
if(inp.checked){
inp.checked = false;
}else{
inp.checked = true;
}
}
}
} </script>
</body>
</html>
Demo
3、class操作
className // 获取所有类名
classList.remove(cls) // 删除指定类
classList.add(cls) // 添加类
4、标签操作
a.创建标签
// 方式一
var tag = document.createElement('a')
tag.innerText = "wupeiqi"
tag.className = "c1"
tag.href = "http://www.cnblogs.com/wupeiqi" // 方式二
var tag = "<a class='c1' href='http://www.cnblogs.com/wupeiqi'>wupeiqi</a>"
b.操作标签
// 方式一
var obj = "<input type='text' />";
xxx.insertAdjacentHTML("beforeEnd",obj);
xxx.insertAdjacentElement('afterBegin',document.createElement('p')) //注意：第一个参数只能是'beforeBegin'、 'afterBegin'、 'beforeEnd'、 'afterEnd' // 方式二
var tag = document.createElement('a')
xxx.appendChild(tag)
xxx.insertBefore(tag,xxx[1])
5、样式操作
var obj = document.getElementById('i1')
obj.style.fontSize = "32px";
obj.style.backgroundColor = "red";
<input onfocus="Focus(this);" onblur="Blur(this);" id="search" value="请输入关键字" style="color: gray;" />
<script>
function Focus(ths){
ths.style.color = "black";
if(ths.value == '请输入关键字' || ths.value.trim() == ""){
ths.value = "";
}
}
function Blur(ths){
if(ths.value.trim() == ""){
ths.value = '请输入关键字';
ths.style.color = 'gray';
}else{
ths.style.color = "black";
}
}
</script>
Demo
6、位置操作
总文档高度
document.documentElement.offsetHeight 当前文档占屏幕高度
document.documentElement.clientHeight 自身高度
tag.offsetHeight 距离上级定位高度
tag.offsetTop 父定位标签
tag.offsetParent 滚动高度
tag.scrollTop /*
clientHeight -> 可见区域：height + padding
clientTop -> border高度
offsetHeight -> 可见区域：height + padding + border
offsetTop -> 上级定位标签的高度
scrollHeight -> 全文高：height + padding
scrollTop -> 滚动高度
特别的：
document.documentElement代指文档根节点
*/
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body style="margin: 0;">
<div style="height: 900px;"> </div>
<div style="padding: 10px;">
<div id="i1" style="height:190px;padding: 2px;border: 1px solid red;margin: 8px;">
<p>asdf</p>
<p>asdf</p>
<p>asdf</p>
<p>asdf</p>
<p>asdf</p>
</div>
</div> <script>
var i1 = document.getElementById('i1'); console.log(i1.clientHeight); // 可见区域：height + padding
console.log(i1.clientTop); // border高度
console.log('=====');
console.log(i1.offsetHeight); // 可见区域：height + padding + border
console.log(i1.offsetTop); // 上级定位标签的高度
console.log('=====');
console.log(i1.scrollHeight); //全文高：height + padding
console.log(i1.scrollTop); // 滚动高度
console.log('====='); </script>
</body>
</html>
test
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<style> body{
margin: 0px;
}
img {
border: 0;
}
ul{
padding: 0;
margin: 0;
list-style: none;
}
.clearfix:after {
content: ".";
display: block;
height: 0;
clear: both;
visibility: hidden;
} .wrap{
width: 980px;
margin: 0 auto;
} .pg-header{
background-color: #303a40;
-webkit-box-shadow: 0 2px 5px rgba(0,0,0,.2);
-moz-box-shadow: 0 2px 5px rgba(0,0,0,.2);
box-shadow: 0 2px 5px rgba(0,0,0,.2);
}
.pg-header .logo{
float: left;
padding:5px 10px 5px 0px;
}
.pg-header .logo img{
vertical-align: middle;
width: 110px;
height: 40px; }
.pg-header .nav{
line-height: 50px;
}
.pg-header .nav ul li{
float: left;
}
.pg-header .nav ul li a{
display: block;
color: #ccc;
padding: 0 20px;
text-decoration: none;
font-size: 14px;
}
.pg-header .nav ul li a:hover{
color: #fff;
background-color: #425a66;
}
.pg-body{ }
.pg-body .catalog{
position: absolute;
top:60px;
width: 200px;
background-color: #fafafa;
bottom: 0px;
}
.pg-body .catalog.fixed{
position: fixed;
top:10px;
} .pg-body .catalog .catalog-item.active{
color: #fff;
background-color: #425a66;
} .pg-body .content{
position: absolute;
top:60px;
width: 700px;
margin-left: 210px;
background-color: #fafafa;
overflow: auto;
}
.pg-body .content .section{
height: 500px;
}
</style>
<body onscroll="ScrollEvent();">
<div class="pg-header">
<div class="wrap clearfix">
<div class="logo">
<a href="#">
<img src="http://core.pc.lietou-static.com/revs/images/common/logo_7012c4a4.pn">
</a>
</div>
<div class="nav">
<ul>
<li>
<a href="#">首页</a>
</li>
<li>
<a href="#">功能一</a>
</li>
<li>
<a href="#">功能二</a>
</li>
</ul>
</div> </div>
</div>
<div class="pg-body">
<div class="wrap">
<div class="catalog">
<div class="catalog-item" auto-to="function1"><a>第1张</a></div>
<div class="catalog-item" auto-to="function2"><a>第2张</a></div>
<div class="catalog-item" auto-to="function3"><a>第3张</a></div>
</div>
<div class="content">
<div menu="function1" class="section">
<h1>第一章</h1>
</div>
<div menu="function2" class="section">
<h1>第二章</h1>
</div>
<div menu="function3" class="section">
<h1>第三章</h1>
</div>
</div>
</div> </div>
<script>
function ScrollEvent(){
var bodyScrollTop = document.body.scrollTop;
if(bodyScrollTop>50){
document.getElementsByClassName('catalog')[0].classList.add('fixed');
}else{
document.getElementsByClassName('catalog')[0].classList.remove('fixed');
} }
</script>
</body>
</html>
Demo-滚动固定
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<style> body{
margin: 0px;
}
img {
border: 0;
}
ul{
padding: 0;
margin: 0;
list-style: none;
}
h1{
padding: 0;
margin: 0;
}
.clearfix:after {
content: ".";
display: block;
height: 0;
clear: both;
visibility: hidden;
} .wrap{
width: 980px;
margin: 0 auto;
} .pg-header{
background-color: #303a40;
-webkit-box-shadow: 0 2px 5px rgba(0,0,0,.2);
-moz-box-shadow: 0 2px 5px rgba(0,0,0,.2);
box-shadow: 0 2px 5px rgba(0,0,0,.2);
}
.pg-header .logo{
float: left;
padding:5px 10px 5px 0px;
}
.pg-header .logo img{
vertical-align: middle;
width: 110px;
height: 40px; }
.pg-header .nav{
line-height: 50px;
}
.pg-header .nav ul li{
float: left;
}
.pg-header .nav ul li a{
display: block;
color: #ccc;
padding: 0 20px;
text-decoration: none;
font-size: 14px;
}
.pg-header .nav ul li a:hover{
color: #fff;
background-color: #425a66;
}
.pg-body{ }
.pg-body .catalog{
position: absolute;
top:60px;
width: 200px;
background-color: #fafafa;
bottom: 0px;
}
.pg-body .catalog.fixed{
position: fixed;
top:10px;
} .pg-body .catalog .catalog-item.active{
color: #fff;
background-color: #425a66;
} .pg-body .content{
position: absolute;
top:60px;
width: 700px;
margin-left: 210px;
background-color: #fafafa;
overflow: auto;
}
.pg-body .content .section{
height: 500px;
border: 1px solid red;
}
</style>
<body onscroll="ScrollEvent();">
<div class="pg-header">
<div class="wrap clearfix">
<div class="logo">
<a href="#">
<img src="http://core.pc.lietou-static.com/revs/images/common/logo_7012c4a4.pn">
</a>
</div>
<div class="nav">
<ul>
<li>
<a href="#">首页</a>
</li>
<li>
<a href="#">功能一</a>
</li>
<li>
<a href="#">功能二</a>
</li>
</ul>
</div> </div>
</div>
<div class="pg-body">
<div class="wrap">
<div class="catalog" id="catalog">
<div class="catalog-item" auto-to="function1"><a>第1张</a></div>
<div class="catalog-item" auto-to="function2"><a>第2张</a></div>
<div class="catalog-item" auto-to="function3"><a>第3张</a></div>
</div>
<div class="content" id="content">
<div menu="function1" class="section">
<h1>第一章</h1>
</div>
<div menu="function2" class="section">
<h1>第二章</h1>
</div>
<div menu="function3" class="section">
<h1>第三章</h1>
</div>
</div>
</div> </div>
<script>
function ScrollEvent(){
var bodyScrollTop = document.body.scrollTop;
if(bodyScrollTop>50){
document.getElementsByClassName('catalog')[0].classList.add('fixed');
}else{
document.getElementsByClassName('catalog')[0].classList.remove('fixed');
} var content = document.getElementById('content');
var sections = content.children;
for(var i=0;i<sections.length;i++){
var current_section = sections[i]; // 当前标签距离顶部绝对高度
var scOffTop = current_section.offsetTop + 60; // 当前标签距离顶部，相对高度
var offTop = scOffTop - bodyScrollTop; // 当前标签高度
var height = current_section.scrollHeight; if(offTop<0 && -offTop < height){
// 当前标签添加active
// 其他移除 active
var menus = document.getElementById('catalog').children;
var current_menu = menus[i];
current_menu.classList.add('active');
for(var j=0;j<menus.length;j++){
if(menus[j] == current_menu){ }else{
menus[j].classList.remove('active');
}
}
break;
} } }
</script>
</body>
</html>
Demo-滚动菜单
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<style> body{
margin: 0px;
}
img {
border: 0;
}
ul{
padding: 0;
margin: 0;
list-style: none;
}
h1{
padding: 0;
margin: 0;
}
.clearfix:after {
content: ".";
display: block;
height: 0;
clear: both;
visibility: hidden;
} .wrap{
width: 980px;
margin: 0 auto;
} .pg-header{
background-color: #303a40;
-webkit-box-shadow: 0 2px 5px rgba(0,0,0,.2);
-moz-box-shadow: 0 2px 5px rgba(0,0,0,.2);
box-shadow: 0 2px 5px rgba(0,0,0,.2);
}
.pg-header .logo{
float: left;
padding:5px 10px 5px 0px;
}
.pg-header .logo img{
vertical-align: middle;
width: 110px;
height: 40px; }
.pg-header .nav{
line-height: 50px;
}
.pg-header .nav ul li{
float: left;
}
.pg-header .nav ul li a{
display: block;
color: #ccc;
padding: 0 20px;
text-decoration: none;
font-size: 14px;
}
.pg-header .nav ul li a:hover{
color: #fff;
background-color: #425a66;
}
.pg-body{ }
.pg-body .catalog{
position: absolute;
top:60px;
width: 200px;
background-color: #fafafa;
bottom: 0px;
}
.pg-body .catalog.fixed{
position: fixed;
top:10px;
} .pg-body .catalog .catalog-item.active{
color: #fff;
background-color: #425a66;
} .pg-body .content{
position: absolute;
top:60px;
width: 700px;
margin-left: 210px;
background-color: #fafafa;
overflow: auto;
}
.pg-body .content .section{
height: 500px;
border: 1px solid red;
}
</style>
<body onscroll="ScrollEvent();">
<div class="pg-header">
<div class="wrap clearfix">
<div class="logo">
<a href="#">
<img src="http://core.pc.lietou-static.com/revs/images/common/logo_7012c4a4.pn">
</a>
</div>
<div class="nav">
<ul>
<li>
<a href="#">首页</a>
</li>
<li>
<a href="#">功能一</a>
</li>
<li>
<a href="#">功能二</a>
</li>
</ul>
</div> </div>
</div>
<div class="pg-body">
<div class="wrap">
<div class="catalog" id="catalog">
<div class="catalog-item" auto-to="function1"><a>第1张</a></div>
<div class="catalog-item" auto-to="function2"><a>第2张</a></div>
<div class="catalog-item" auto-to="function3"><a>第3张</a></div>
</div>
<div class="content" id="content">
<div menu="function1" class="section">
<h1>第一章</h1>
</div>
<div menu="function2" class="section">
<h1>第二章</h1>
</div>
<div menu="function3" class="section" style="height: 200px;">
<h1>第三章</h1>
</div>
</div>
</div> </div>
<script>
function ScrollEvent(){
var bodyScrollTop = document.body.scrollTop;
if(bodyScrollTop>50){
document.getElementsByClassName('catalog')[0].classList.add('fixed');
}else{
document.getElementsByClassName('catalog')[0].classList.remove('fixed');
} var content = document.getElementById('content');
var sections = content.children;
for(var i=0;i<sections.length;i++){
var current_section = sections[i]; // 当前标签距离顶部绝对高度
var scOffTop = current_section.offsetTop + 60; // 当前标签距离顶部，相对高度
var offTop = scOffTop - bodyScrollTop; // 当前标签高度
var height = current_section.scrollHeight; if(offTop<0 && -offTop < height){
// 当前标签添加active
// 其他移除 active // 如果已经到底部，现实第三个菜单
// 文档高度 ＝ 滚动高度 + 视口高度 var a = document.getElementsByClassName('content')[0].offsetHeight + 60;
var b = bodyScrollTop + document.documentElement.clientHeight;
console.log(a+60,b);
if(a == b){
var menus = document.getElementById('catalog').children;
var current_menu = document.getElementById('catalog').lastElementChild;
current_menu.classList.add('active');
for(var j=0;j<menus.length;j++){
if(menus[j] == current_menu){ }else{
menus[j].classList.remove('active');
}
}
}else{
var menus = document.getElementById('catalog').children;
var current_menu = menus[i];
current_menu.classList.add('active');
for(var j=0;j<menus.length;j++){
if(menus[j] == current_menu){ }else{
menus[j].classList.remove('active');
}
}
} break;
} } }
</script>
</body>
</html>
Demo-滚动高度
7、提交表单
document.geElementById('form').submit()
8、其他操作
console.log 输出框
alert 弹出框
confirm 确认框 // URL和刷新
location.href 获取URL
location.href = "url" 重定向
location.reload() 重新加载 // 定时器
setInterval 多次定时器
clearInterval 清除多次定时器
setTimeout 单次定时器
clearTimeout 清除单次定时器
三、事件
对于事件需要注意的要点：
- this
- event
- 事件链以及跳出
this标签当前正在操作的标签，event封装了当前事件的内容。
实例
<!DOCTYPE html>
<html>
<head>
<meta charset='utf-8' />
<title></title> <style>
.gray{
color:gray;
}
.black{
color:black;
}
</style>
<script type="text/javascript">
function Enter(){
var id= document.getElementById("tip")
id.className = 'black';
if(id.value=='请输入关键字'||id.value.trim()==''){
id.value = ''
}
}
function Leave(){
var id= document.getElementById("tip")
var val = id.value;
if(val.length==0||id.value.trim()==''){
id.value = '请输入关键字'
id.className = 'gray';
}else{
id.className = 'black';
}
}
</script>
</head>
<body>
<input type='text' class='gray' id='tip' value='请输入关键字' onfocus='Enter();' onblur='Leave();'/>
</body>
</html>
搜索框
<!DOCTYPE html>
<html>
<head>
<meta charset='utf-8' >
<title>欢迎blue shit莅临指导 </title>
<script type='text/javascript'>
function Go(){
var content = document.title;
var firstChar = content.charAt(0)
var sub = content.substring(1,content.length)
document.title = sub + firstChar;
}
setInterval('Go()',1000);
</script>
</head>
<body>
</body>
</html>
跑马灯
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.style_before {
color: lightgrey;
}
.style_after {
color: black;
}
</style>
</head>
<body>
<h3>爱好</h3>
<div>
<ul id="i1">
<li><input type="checkbox" value="1">篮球</li>
<li><input type="checkbox" value="2">足球</li>
<li><input type="checkbox" value="3">乒乓球</li>
</ul>
</div>
<button onclick="Cheakall()">全选</button>
<button onclick="Cancleall()">取消全选</button>
<button onclick="Reversall()">反选</button>
<script>
function Cheakall() {
var i1 = document.getElementById("i1");
var cheak = i1.getElementsByTagName("input");
for (i=0;i<cheak.length;i++) {
cheak[i].checked = true;
}
}
function Cancleall() {
var i1 = document.getElementById("i1");
var cheak = i1.getElementsByTagName("input");
for (i=0;i<cheak.length;i++) {
cheak[i].checked = false;
}
}
function Reversall() {
var i1 = document.getElementById("i1");
var cheak = i1.getElementsByTagName("input");
for (i=0;i<cheak.length;i++) {
if (cheak[i].checked) {
cheak[i].checked = false;
}else {
cheak[i].checked = true;
}
}
}
</script>
</body>
</html>
全选、反选
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.hide {
display: none;
}
.c1 {
position: fixed;
top: 0;
right: 0;
bottom: 0;
left: 0;
background: rgba(0,0,0,.6);
z-index: 2;
}
.c2 {
position: fixed;
width: 400px;
height: 300px;
top: 50%;
left: 50%;
z-index: 3;
margin-top: -150px;
margin-left: -200px;
background-color: white;
text-align: center;
padding-top: 150px;
}
</style>
</head>
<body>
<div><input type="button" value="登录" onclick="hihi()"></div>
<div id="cc1" class="c1 hide"></div>
<div id="cc2" class="c2 hide">
<div>用户名：<input type="text"></div>
<div>密 码：<input type="text"></div>
<input type="button" value="确定">
<input type="button" value="取消" onclick="hisl()">
</div> <script>
function hihi() {
document.getElementById("cc1").classList.remove("hide");
document.getElementById("cc2").classList.remove("hide");
}
function hisl() {
document.getElementById("cc1").classList.add("hide");
document.getElementById("cc2").classList.add("hide");
}
</script>
</body>
</html>
模态对话框
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
body{
margin: 0;
background-color: #dddddd;
}
.w{
margin: 0 auto;
width: 980px;
}
.pg-header{
background-color: black;
color: white;
height: 48px;
}
.pg-body .menu{
position: absolute;
left: 200px;
width: 180px;
background-color: white;
float: left;
}
.pg-body .menu .active{
background-color: #425a66;
color: white;
}
.pg-body .fixed{
position: fixed;
top: 10px;
}
.pg-body .content{
position: absolute;
left: 385px;
right: 200px;
background-color: white;
float: left;
}
.pg-body .content .item{
height: 900px;
}
</style> </head>
<body onscroll="Hua();">
<div class="pg-header">
<div class="w"></div>
</div>
<div class="pg-body">
<div id="menu" class="menu">
<ul>
<li>第一章</li>
<li>第二章</li>
<li>第三章</li>
</ul>
</div>
<div id="content" class="content">
<div class="item">床前明月管</div>
<div class="item">疑是地上霜</div>
<div class="item" style="height: 100px">我是郭德纲</div>
</div>
</div> <script>
function Hua() {
var xo = document.getElementById("menu");
var huaGao = document.body.scrollTop;
if (document.body.scrollTop>48){
xo.classList.add("fixed");
}else {
xo.classList.remove("fixed");
} var bod = document.body.offsetHeight;
var conAbs = document.getElementsByClassName("content")[0].offsetHeight;
var ck = document.documentElement.clientHeight;
// console.log((bod + conAbs) == (ck + huaGao));
if ((bod + conAbs) == (ck + huaGao)) {
var lenLi = xo.getElementsByTagName("li");
for (var i=0;i<lenLi.length;i++){
if (i == lenLi.length - 1){
lenLi[i].className = "active";
}else {
lenLi[i].className = "";
}
}
return
} var item = document.getElementById("content").children;
for (var i=0;i<item.length;i++){
var currentItem = item[i];
var currentItemBodyTop = currentItem.offsetTop + currentItem.offsetParent.offsetTop;
var currentItemWindowTop = currentItemBodyTop - huaGao; var currentHeight = currentItem.offsetHeight;
var bottomHeight = currentItemBodyTop + currentHeight; var ziJi = xo.getElementsByTagName("li")[i];
if (currentItemWindowTop<0 && huaGao < bottomHeight){
ziJi.className = "active";
} else {
ziJi.className = "";
} }
} </script>
</body>
</html>
书签章节
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
ul{
list-style: none;
padding: 0;
margin: 0;
}
ul li{
float: left;
background-color: #2459a2;
color: white;
padding: 8px 10px;
}
.clearfix:after{
display: block;
content: '.';
height: 0;
visibility: hidden;
clear: both;
}
.hide{
display: none;
}
.tab-menu .title{
background-color: #dddddd;
}
.tab-menu .title .active{
background-color: #0099dd;
color: black;
}
.tab-menu .content{
border: 1px solid #dddddd;
min-height: 150px;
}
ul li:hover {
cursor: pointer;
}
</style>
</head>
<body>
<div style="width: 400px; margin: 0 auto;">
<div class="tab-menu">
<div class="title clearfix">
<ul>
<li target="h1" class="active" onclick="Show(this);">索尼</li>
<li target="h2" onclick="Show(this);">谷歌</li>
<li target="h3" onclick="Show(this);">腾讯</li>
</ul>
</div>
<div id="content" class="content">
<div con="h1">1...</div>
<div con="h2" class="hide">2...</div>
<div con="h3" class="hide">3...</div>
</div>
</div>
</div> <script>
function Show(ths) {
var Showli = ths;
var littarget = Showli.getAttribute("target");
var liclass = Showli.parentNode.children;
for (var i=0;i<liclass.length;i++) {
if (liclass[i].getAttribute("target") == littarget) {
liclass[i].classList.add("active");
}else {
liclass[i].classList.remove("active");
}
}
var liycontent = document.getElementById("content").children;
for (var i=0;i<liycontent.length;i++) {
if (liycontent[i].getAttribute("con") == littarget) {
liycontent[i].className = "";
}else {
liycontent[i].className = "hide";
}
}
}
</script>
</body>
</html>
菜单
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.go-top {
position: fixed;
right: 28px;
bottom: 19px;
width: 38px;
height: 40px;
background-color: aliceblue;
}
.hide {
display: none;
}
</style>
</head>
<body onscroll="Func();">
<div style="height: 2000px"></div>
<div id="i2" class="go-top hide">
<a onclick="GoTop();">返回顶部</a>
</div>
<script>
function Func() {
var scrolltop = document.body.scrollTop;
var ii = document.getElementById("i2");
if (scrolltop>300) {
ii.classList.remove("hide");
}else {
ii.classList.add("hide");
}
}
function GoTop() {
document.body.scrollTop = 0;
}
</script>
</body>
</html>
返回顶部
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