文档对象模型(Document Object Model,DOM)是一种用于HTML和XML文档的编程接口。它给文档提供了一种结构化的表示方法,可以改变文档的内容和呈现方式。我们最为关心的是,DOM把网页和脚本以及其他的编程语言联系了起来。DOM属于浏览器,而不是JavaScript语言规范里的规定的核心内容。

一、查找元素

1、直接查找

xxxxElementsxxx(表示所有的,找到的元素会放到一个数组中)

document.getElementById             根据ID获取一个标签
document.getElementsByName          根据name属性获取标签集合
document.getElementsByClassName     根据class属性获取标签集合
document.getElementsByTagName       根据标签名获取标签集合

2、间接查找

查找标签的同时把其下的文本内容也找出

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
我们可以通过xxx.childNodes(其他的同理).nodeType[x]判断我们得到的是文本还是标签 xxx.childNodes(其他的同理)[x].nodeType = 1 标签 xxx.childNodes(其他的同理)[x].nodeType = 3 文本

只是查找标签,不包括文本内容

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
 

 (用于获取普通标签中间的内容)

<body>
    <div id="d1">老男孩<span>666</span></div>
<script>
    ret = document.getElementById("d1");
    console.log(ret.innerText);//--------->老男孩666
    console.log(ret.innerHTML);//--------->老男孩<span>666</span>
</script>
</body>

 (获取input标签和下拉标签中value值)

<body>
    <input id="d1" type="text">
    <select id="d2">
        <option value="1">上海</option>
        <option value="2">北京</option>
    </select>
<script>
    ret1 = document.getElementById("d1");
    ret2= document.getElementById("d2");
    console.log(ret1.value); //--------获取你输入的内容
    console.log(ret2.value); //--------获取你选择项的value值
</script>

 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

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
<!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%;
            background-color: white;
            z-index: 3;
            margin-top: -150px;
            margin-left: -200px;
        }
    </style>
</head>
<body>
    <div>
        <table>
            <tr>
                <td>1</td>
                <td>1</td>
                <td><input type="button" value="点我" onclick="show()"></td>
            </tr>
        </table>
    </div>
    <div id="show" class="c1 hide" ></div>
    <div id="hide" class="c2 hide">
        用户名:<input type="text">
        密码:<input type="password">
        <input  type="button" value="确定" onclick="a()">
        <input   type="button" value="取消" onclick="a()">
    </div>
    <script>

        function show() {
            document.getElementById("show").classList.remove("hide");
            document.getElementById("hide").classList.remove("hide");
        }
        function a() {
            document.getElementById("show").classList.add("hide");
            document.getElementById("hide").classList.add("hide");
        }
    </script>
</body>
</html>
模态对话框实例

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"; 

 1>input中操作

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
  <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>
</body>
</html>
输入框

2> checkbox复选框操作

   <div  id="l1">
        <ul>
            <li><input type="checkbox" value="1">篮球</li>
            <li><input type="checkbox" value="2">足球</li>
            <li><input type="checkbox" value="3">排球</li>
        </ul>
    </div>
    <script>
        var check = document.getElementById("l1");
        var ret = check.getElementsByTagName("input"); //我们可以通过找到一个标签x后,通过x.get...找x标签后面的某一个标签
        var tt = ret[1].checked;  //可以通过x.checked获取复选框是否被选中的状态
        ret[2].checked = true;   //我们也可以通过设置checked的状态来控制是否被选中
        console.log(tt)
    </script>
复选框操作

3>全选、取消、反选

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <input type="submit" value="全选" onclick="f1()">
    <input type="submit" value="取消" onclick="f2()">
    <input type="submit" value="反选" onclick="f3()">
    <table>
        <thead>
            <tr>
                <th>序号</th>
                <th>用户名</th>
                <th>年龄</th>
            </tr>
        </thead>
        <tbody id="d1">
            <tr>
                <td><input type="checkbox"></td>
                <td>alex</td>
                <td>18</td>
            </tr>
            <tr>
                <td><input type="checkbox"></td>
                <td>alex</td>
                <td>18</td>
            </tr>
            <tr>
                <td><input type="checkbox"></td>
                <td>alex</td>
                <td>18</td>
            </tr>
        </tbody>
    </table>
    <script>
        function f1() {
            var tag =document.getElementById("d1");
            var all = tag.getElementsByTagName("input");
            for(var i=0;i<all.length;i++){
                var one = all[i];
                one.checked = true;
            }
        }
        function f2() {
            var tag =document.getElementById("d1");
            var all = tag.getElementsByTagName("input");
            for(var i=0;i<all.length;i++){
                var one = all[i];
                one.checked = false;
            }
        }
        function f3() {
            var tag =document.getElementById("d1");
            var all = tag.getElementsByTagName("input");
            for(var i=0;i<all.length;i++){
                var one = all[i];
                if (one.checked){
                    one.checked = false;
                }else {
                    one.checked = true;
                }
            }
        }
    </script>
</body>
</html>
全选、反选

4>模态弹框

<!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%;
            background-color: white;
            z-index: 3;
            margin-top: -150px;
            margin-left: -200px;
        }
    </style>
</head>
<body>
    <input type="button" value="点我" onclick="show()">
    <div id="show" class="c1 hide" ></div>
    <div id="hide" class="c2 hide">
        <input type="text">     用户名
        <input type="password"> 密码
        <input  type="button" value="确定"style="display: block">
        <input   type="button" value="取消" onclick="a()">
    </div>
    <script>
        function show() {
            document.getElementById("show").classList.remove("hide");
            document.getElementById("hide").classList.remove("hide");
        }
        function a() {
            document.getElementById("show").classList.add("hide");
            document.getElementById("hide").classList.add("hide");
        }
    </script>
</body>
</html>
模态弹框

5>return  = false 表示当同时要执行俩个以上操作时,如果第一个操作的返回值时false,那么第二个操作不再执行

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="111">
        <div id="d1">
             <input type="text">
        </div>
        <input type="submit" value="提交" onclick="return f1()">

    </form>
    <script>
        function f1() {
            var inp = document.getElementById("d1").getElementsByTagName("input");
            for (var i = 0; i < inp.length; i++) {
                var val = inp[i].value;
                if (val.length == 0) {
                    alert("请输入内容!");
                    return false;     //表示后面的的跳转不在执行
                } else {
                    return true
                }
            }
        }

    </script>

</body>
</html>
return = false

 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>
text
<!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>
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>
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>
滚动高度

7、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。

 

posted on 2016-07-12 10:02  23云恋49枫  阅读(292)  评论(0编辑  收藏  举报