Web開發（初級）- DOM

時間 2020-05-29

標籤 web 開發初級 dom 欄目 HTML 简体版

原文原文鏈接

文檔對象模型（Document Object Model，DOM）是一種用於HTML和XML文檔的編程接口。它給文檔提供了一種結構化的表示方法，能夠改變文檔的內容和呈現方式。咱們最爲關心的是，DOM把網頁和腳本以及其餘的編程語言聯繫了起來。DOM屬於瀏覽器，而不是JavaScript語言規範裏的規定的核心內容。javascript

1、查找元素

一、直接查找html

document.getElementById             根據ID獲取一個標籤
document.getElementsByName          根據name屬性獲取標籤集合
document.getElementsByClassName     根據class屬性獲取標籤集合
document.getElementsByTagName       根據標籤名獲取標籤集合

二、間接查找java

parentNode          // 父節點
childNodes          // 全部子節點
firstChild          // 第一個子節點
lastChild           // 最後一個子節點
nextSibling         // 下一個兄弟節點
previousSibling     // 上一個兄弟節點
 
parentElement           // 父節點標籤元素
children                // 全部子標籤
firstElementChild       // 第一個子標籤元素
lastElementChild        // 最後一個子標籤元素
nextElementtSibling     // 下一個兄弟標籤元素
previousElementSibling  // 上一個兄弟標籤元素

2、操做

一、內容node

innerText   文本
outerText
innerHTML   HTML內容
innerHTML  
value       值

二、屬性python

attributes                // 獲取全部標籤屬性
setAttribute(key,value)   // 設置標籤屬性
getAttribute(key)         // 獲取指定標籤屬性
 
/*
var atr = document.createAttribute("class");
atr.nodeValue="democlass";
document.getElementById('n1').setAttributeNode(atr);
*/

<!-- 如下demo是利用操做屬性，實現表格的全選，取消及反選 -->

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <input type="button" value="全選"  onclick="CheckAll();"/>
    <input type="button" value="取消" onclick="CancelAll();"/>
    <input type="button" value="反選" 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>

三、class操做web

className                // 獲取全部類名
classList.remove(cls)    // 刪除指定類
classList.add(cls)       // 添加類

四、標籤操做編程

a.建立標籤瀏覽器

// 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.操做標籤app

// 方式一
var obj = "<input type='text' />";
xxx.insertAdjacentHTML("beforeEnd",obj);
xxx.insertAdjacentElement('afterBegin',document.createElement('p'))
 
//注意：第一個參數只能是'beforeBegin'、 'afterBegin'、 'beforeEnd'、 'afterEnd'
 
// 方式二
var tag = document.createElement('a')
xxx.appendChild(tag)
xxx.insertBefore(tag,xxx[1])

五、樣式操做編程語言

var obj = document.getElementById('i1')
 
obj.style.fontSize = "32px";
obj.style.backgroundColor = "red";

<input onfocus="Focus(this);" onblur="Blur(this);" id="search" value="請輸入關鍵字" style="color: gray;" />

<script>
    function Focus(ths){
        ths.style.color = "black";
        if(ths.value == '請輸入關鍵字' || ths.value.trim() == ""){
            ths.value = "";
        }
    }

    function Blur(ths){
        if(ths.value.trim() == ""){
            ths.value = '請輸入關鍵字';
            ths.style.color = 'gray';
        }else{
            ths.style.color = "black";
        }
    }
</script>

六、位置操做

總文檔高度
document.documentElement.offsetHeight
  
當前文檔佔屏幕高度
document.documentElement.clientHeight
  
自身高度
tag.offsetHeight
  
距離上級定位高度
tag.offsetTop
  
父定位標籤
tag.offsetParent
  
滾動高度
tag.scrollTop
 
/*
    clientHeight -> 可見區域：height + padding
    clientTop    -> border高度
    offsetHeight -> 可見區域：height + padding + border
    offsetTop    -> 上級定位標籤的高度
    scrollHeight -> 全文高：height + padding
    scrollTop    -> 滾動高度
    特別的：
        document.documentElement代指文檔根節點
*/

<!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); // 可見區域：height + padding
        console.log(i1.clientTop);    // border高度
        console.log('=====');
        console.log(i1.offsetHeight); // 可見區域：height + padding + border
        console.log(i1.offsetTop);    // 上級定位標籤的高度
        console.log('=====');
        console.log(i1.scrollHeight);   //全文高：height + padding
        console.log(i1.scrollTop);      // 滾動高度
        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/p_w_picpaths/common/logo_7012c4a4.pn">
            </a>
        </div>
        <div class="nav">
            <ul>
                <li>
                    <a  href="#">首頁</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張</a></div>
            <div class="catalog-item" auto-to="function2"><a>第2張</a></div>
            <div class="catalog-item" auto-to="function3"><a>第3張</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-滾動固定

<!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/p_w_picpaths/common/logo_7012c4a4.pn">
            </a>
        </div>
        <div class="nav">
            <ul>
                <li>
                    <a  href="#">首頁</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張</a></div>
            <div class="catalog-item" auto-to="function2"><a>第2張</a></div>
            <div class="catalog-item" auto-to="function3"><a>第3張</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];

                // 當前標籤距離頂部絕對高度
                var scOffTop = current_section.offsetTop + 60;

                // 當前標籤距離頂部，相對高度
                var offTop = scOffTop - bodyScrollTop;

                // 當前標籤高度
                var height = current_section.scrollHeight;

                if(offTop<0 && -offTop < height){
                    // 當前標籤添加active
                    // 其餘移除 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-滾動菜單

<!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/p_w_picpaths/common/logo_7012c4a4.pn">
            </a>
        </div>
        <div class="nav">
            <ul>
                <li>
                    <a  href="#">首頁</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張</a></div>
            <div class="catalog-item" auto-to="function2"><a>第2張</a></div>
            <div class="catalog-item" auto-to="function3"><a>第3張</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];

                // 當前標籤距離頂部絕對高度
                var scOffTop = current_section.offsetTop + 60;

                // 當前標籤距離頂部，相對高度
                var offTop = scOffTop - bodyScrollTop;

                // 當前標籤高度
                var height = current_section.scrollHeight;

                if(offTop<0 && -offTop < height){
                    // 當前標籤添加active
                    // 其餘移除 active

                    // 若是已經到底部，現實第三個菜單
                    // 文檔高度 ＝ 滾動高度 + 視口高度

                    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-滾動高度

七、提交表單

document.geElementById('form').submit()

八、其餘操做

console.log                 輸出框
alert                       彈出框
confirm                     確認框
  
// URL和刷新
location.href               獲取URL
location.href = "url"       重定向
location.reload()           從新加載
  
// 定時器
setInterval                 屢次定時器
clearInterval               清除屢次定時器
setTimeout                  單次定時器
clearTimeout                清除單次定時器

3、事件

對於事件須要注意的要點：

this
event
事件鏈以及跳出

this標籤當前正在操做的標籤，event封裝了當前事件的內容。

<!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=='請輸入關鍵字'||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 = '請輸入關鍵字'
                    id.className = 'gray';
                }else{
                    id.className = 'black';
                }
            }
        </script>
    </head>
    <body>
        <input type='text' class='gray' id='tip' value='請輸入關鍵字' onfocus='Enter();'  onblur='Leave();'/>
    </body>
</html>

搜索框

<!DOCTYPE html>
<html>
    <head>
        <meta charset='utf-8' >
        <title>歡迎blue shit蒞臨指導&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>

×××燈

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .go-top {
            position: fixed;
            right: 200px;
            bottom: 100px;
            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();">返回頂部</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>

返回頂部

相關標籤/搜索

每日一句

每一个你不满意的现在，都有一个你没有努力的曾经。