DOM相关知识

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2024-09-22 20:43:06 219人阅读

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="http://www.mamicode.com/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.mamicode.com/‘http://www.cnblogs.com/wupeiqi‘>wupeiqi"

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="http://www.mamicode.com/请输入关键字" style="color: gray;" />

    <script>
        function Focus(ths){
            ths.style.color = "black";
            if(ths.value =http://www.mamicode.com/= ‘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

技术分享

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=http://www.mamicode.com/=‘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=http://www.mamicode.com/‘请输入关键字‘ onfocus=‘Enter();‘  onblur=‘Leave();‘/>>

搜索框

<!DOCTYPE html>
<html>
    <head>
        <meta charset=‘utf-8‘ >
        <title>欢迎blue shit莅临指导&nbsp;&nbsp;</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="http://www.mamicode.com/1">篮球</li>
            <li><input type="checkbox" value="http://www.mamicode.com/2">足球</li>
            <li><input type="checkbox" value="http://www.mamicode.com/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>

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