lovecoding
/
W250913


			
				
					
						
						
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							<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        li{
            list-style: none;
        }
        .box{
            width: 500px;
            height: 300px;
            border:3px solid black;
            margin: 100px auto;
        }
        .tab-nav{
            height: 50px;
            background-color: black;
        }
        .tab-nav .nav-btn{
            color: #fff;
            float: left;
            width: 100px;
            text-align: center;
            line-height: 50px;
        }
        .tab-nav .active{
            background-color: #999;
            color: #111;
        }
        .tab-content .content-item{
            display: none;
            padding: 20px;
        }
        .tab-content .active{
            display: block;
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="tab-nav">
            <ul>
                <li class="nav-btn active">第一节课</li>
                <li class="nav-btn">第二节课</li>
                <li class="nav-btn">第三节课</li>
            </ul>
        </div>
        <div class="tab-content">
            <div class="content-item active">第一节课内容</div>
            <div class="content-item">第二节课内容</div>
            <div class="content-item">第三节课内容</div>
        </div>
    </div>
    <script>
        // 获取所有的按钮
        var aNavBtns = document.getElementsByClassName("nav-btn");
        // 获取所有的内容
        var aContentItems = document.getElementsByClassName("content-item");

        for(var i=0;i<aNavBtns.length;i++){
            // 循环过程中为每一个按钮添加一个索引值
            aNavBtns[i].index = i;
            // 循环所有按钮 绑定点击事件
            aNavBtns[i].onmouseover = function(){
                // 清除所有按钮的active类名
                for(var j=0;j<aNavBtns.length;j++){
                   aNavBtns[j].classList.remove("active"); 
                   aContentItems[j].classList.remove("active");
                }
                // 给当前点击的按钮添加active类名
                this.classList.add("active");

                // 给对应内容添加active类名 让其显示
                aContentItems[this.index].classList.add("active");
                // console.log(this.index)
            }
        }
    </script>
</body>
</html>