/** * Created by EDUASK on 2016/5/20. */ $(function(){ //引入id标签; var navtive=$("#native"); //设置导航标签为置顶; var offsetTop=navtive.offset().top; //定义一个监听高度; var scrollHeight=$(document).scrollTop; fn(navtive,offsetTop); //设置监听事件; $(window).scroll(function(){ fn(navtive,offsetTop); }); //调用方法; function fn(navtive,offsetTop){ var scrollHeight=$(document).scrollTop(); if(offsetTop>scrollHeight){ navtive.css("top",offsetTop); }else{ navtive.css("top",scrollHeight); } } });
2. html代码
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>监听导航滚动置顶</title> <!--css样式;--> <style type="text/css"> /*添加导航条的样式; */ #native{ background: blue; width: 100%; height: 20px; color: red; position: absolute; top: 100px; left: 0; text-align: center; } </style> <script src="https://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script> <script type="text/javascript" src="https://www.jb51.net/监听导航滚动置顶.js"> </script> </head> <body> <p>ddddd</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <div>欢迎访问我的导航条</div> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <a href="#top" >回到顶部</a> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> <p>aaaaaaaaaaaa</p> </body> </html>
感兴趣的朋友可以使用在线HTML/CSS/JavaScript代码运行工具：测试运行效果。
更多关于jQuery相关内容感兴趣的读者可查看本站专题：《jQuery常见事件用法与技巧总结》、《jQuery常用插件及用法总结》、《jQuery操作json数据技巧汇总》、《jQuery扩展技巧总结》、《jQuery常见经典特效汇总》及《jquery选择器用法总结》