最近在重新学习JavaScript，手写了一个tabs标签页。

  话不多说，直接开始。  

  首先，是前端页面。

javascript表格标签 js标签栏_ico

 

图1 tabs

先来把tabs分解一下：

javascript表格标签 js标签栏_html_02

图2 tabs分解

首先，一个大的框div，上面红色的框是导航栏nav，导航栏里是一个无序列表ul，里面三个li标签（黄色的框），li标签里两个绿色标签是两个span，一个用来放导航的名字，一个用来放导航关闭的icon，右边是一个button，用来添加新的导航栏及内容；下方是导航栏的内容section。

导航tabs.html代码如下：

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <main>
        <div class="tabsbox" id="tab">
            <!-- tab标签 -->
            <nav class="firstnav">
                <ul>
                    <li class="liactive"><span>测试1</span><span class="icon-guanbi">X</span></li>
                    <li><span>测试2</span><span class="icon-guanbi">X</span></li>
                    <li><span>测试3</span><span class=" icon-guanbi">X</span></li>
                </ul>
                <div class="tabadd">
                    <span>+</span>
                </div>
            </nav>

            <!-- tab内容 -->
            <div class="tabscon">
                <section class="conactive">测试内容1</section>
                <section>测试内容2</section>
                <section>测试内容3</section>
            </div>
        </div>
    </main>

    <script src="js/tabs.js"></script>
</body>

</html>
<style>
 * {
    margin: 0;
    padding: 0;
}

ul li {
    list-style: none;
}

main {
    width: 960px;
    height: 500px;
    border-radius: 10px;
    margin: 50px auto;
}

main h4 {
    height: 100px;
    line-height: 100px;
    text-align: center;
}

.tabsbox {
    width: 900px;
    margin: 0 auto;
    height: 400px;
    border: 1px solid lightsalmon;
    position: relative;
}

nav ul {
    overflow: hidden;
}

nav ul li {
    float: left;
    width: 100px;
    height: 50px;
    line-height: 50px;
    text-align: center;
    border-right: 1px solid #ccc;
    position: relative;
}

nav ul li.liactive {
    border-bottom: 2px solid #fff;
    z-index: 9;
}

#tab input {
    width: 80%;
    height: 60%;
}

nav ul li span:last-child {
    position: absolute;
    user-select: none;
    font-size: 12px;
    top: -18px;
    right: 0;
    display: inline-block;
    height: 20px;
}

.tabadd {
    position: absolute;
    /* width: 100px; */
    top: 0;
    right: 0;
}

.tabadd span {
    display: block;
    width: 20px;
    height: 20px;
    line-height: 20px;
    text-align: center;
    border: 1px solid #ccc;
    float: right;
    margin: 10px;
    user-select: none;
}

.tabscon {
    width: 100%;
    height: 300px;
    position: absolute;
    padding: 30px;
    top: 50px;
    left: 0px;
    box-sizing: border-box;
    border-top: 1px solid #ccc;
}

.tabscon section,
.tabscon section.conactive {
    display: none;
    width: 100%;
    height: 100%;
}

.tabscon section.conactive {
    display: block;
}
</style>

由于给导航栏增删查改的js代码很多，我单独用一个js文件写tabs.js，在tabs.html里引用就行。

实现的导航栏功能有：

　　1）导航栏的切换功能

       2）增加导航栏的功能

       3）删除导航栏的功能

   tabs.js代码如下：

1 var that;
  2 class Tab {
  3     constructor(id){
  4         that = this;
  5         //获取元素
  6         this.main = document.querySelector(id);
  7        
  8         this.add = this.main.querySelector('.tabadd');
  9         //li的父元素
 10         this.ul = this.main.querySelector('.firstnav ul:first-child');
 11         //section的父元素
 12         this.fsection = this.main.querySelector('.tabscon');
 13         this.init();
 14     }
 15     //初始化操作
 16     init(){
 17         this.updateNode();
 18         this.add.onclick = this.addTab;
 19         for(let i = 0;i<this.lis.length;i++){
 20             this.lis[i].index = i;
 21             this.lis[i].onclick = this.toggleTab;
 22             this.remove[i].onclick = this.removeTab;
 23             this.spans[i].ondblclick = this.editTab;
 24             this.sections[i].ondblclick = this.editTab;
 25         }
 26     }
 27     //获取li跟section
 28     updateNode(){
 29         this.lis = this.main.querySelectorAll('li');
 30         this.sections = this.main.querySelectorAll('section');
 31         this.remove = this.main.querySelectorAll('.icon-guanbi');
 32         this.spans = this.main.querySelectorAll('.firstnav li span:first-child')
 33     }
 34     //1.切换功能
 35     toggleTab(){
 36 
 37         that.clearClass();
 38         this.className = 'liactive';
 39         that.sections[this.index].className = 'conactive';
 40     }
 41     clearClass(){
 42         for(let i = 0;i<this.lis.length;i++){
 43             this.lis[i].className = '';
 44             this.sections[i].className = '';
 45         }
 46     }
 47     //2.添加功能
 48     addTab(){
 49         that.clearClass();
 50        //1)添加li元素和section
 51         var random = Math.random()
 52         var li = '<li class="liactive"><span>新选项卡</span><span class="iconfont icon-guanbi">X</span></li>';
 53         var section = '<section class="conactive">'+random+'</section>';
 54        
 55        //2）把两个元素添加到对应的父级元素中
 56         that.ul.insertAdjacentHTML('beforeend',li);
 57         that.fsection.insertAdjacentHTML('beforeend',section);
 58         that.init();
 59     }
 60     //3.删除功能
 61     removeTab(e){
 62         e.stopPropagation();
 63         var index = this.parentNode.index;
 64         console.log(index);
 65         //删除对应节点
 66         that.lis[index].remove();
 67         that.sections[index].remove();
 68         //删除后及时更新页面中的节点
 69         that.init();
 70         //如果当前页面有选中状态，就不用执行下面的步骤
 71         if(document.querySelector('.liactive')) return;
 72         //让index前一个处于选中状态
 73         index--;
 74         that.lis[index] && that.lis[index].click();
 75     }
 76     //4.修改功能
 77     editTab(){
 78         let str = this.innerHTML;
 79         // console.log(str);
 80         //禁止双击选中文字
 81         window.getSelection ? window.getSelection().removeAllRanges() : document.selection.empty(); 
 82         this.innerHTML='<input type="text">'
 83         let input = this.children[0];
 84         input.value = str;
 85         input.select();
 86         //input失去焦点后变回span
 87         input.onblur = function(){
 88             this.parentNode.innerHTML= this.value;
 89         }
 90         //按回车也能
 91         input.onkeyup = function(e){
 92             if(e.keyCode == 13){
 93                  this.blur();//获得焦点
 94             }
 95            
 96         }
 97         
 98     }
 99 }
100  new Tab('#tab');
101 // tab.init();