导航栏的在线

1 month ago · d89427dbf9
parent e94d590d1b
commit d89427dbf9
1 changed files with 47 additions and 0 deletions
--- a/导航栏再现.html
+++ b/导航栏再现.html
@ -0,0 +1,47 @@
 <!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>
        .box1{
            position: fixed;
            width: 100%;
            height: 50px;
            background-color: #e4e4e4;
            text-align: center;
            line-height: 50px;
            top:-80px;
        }
        .box2{
            width: 100%;
            height: 1800px;
            background-color: pink;
           display: flex;
           align-items: center;
        }
        .box3{
            width: 200px;
            background-color: aqua;
        }
    </style>
 </head>
 <body>
    <div class="box1">我又出现了</div>
    <div class="box2">
        <div class="box3">滑到这里再出现</div>
    </div>
    <script>
        const box1=document.querySelector('.box1')
        const box3=document.querySelector('.box3')
        window.addEventListener('scroll',function(){
            const n=document.documentElement.scrollTop
     box1.style.top=n>=box3.offsetTop ? 0 : '-80px'
 })
    </script>
 </body>
 </html>