//当滚动条的位置处于距顶部100像素以下时,跳转链接出现,否则消失 $(function () { $(window).scroll(function () { if ($(window).scrollTop() > 100) { $("#back-to-top").fadeIn(1000); console.log($(window).scrollTop()) console.log(window.innerHeight) } else { $("#back-to-top").fadeOut(1000); } }); //当点击跳转链接后,回到页面顶部位置 $("#back-to-top").click(function () { $('body,html').animate({scrollTop: 0}, 1000); return false; }); }); 我写了小demo 明明就可以触发 <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <meta name="viewport" content="width=device-width,user-scalable=no,initial-scale=1.0"/> <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/> <meta name="keywords" content=""/> <meta name="description" content=""/> <meta name="robots" content="all"> <meta name="renderer" content="webkit"> <style> *{ margin: 0;padding: 0; } div{ width: 100%; height:1880px; background: #BDBDBD; } .fix{ width: 50px; height:50px; background: #B72712; position: fixed; right: 0; bottom: 50px; color: #ffffff; font-size: 18px; text-align: center; display: none; } </style> </head> <body> <div id="div"> 我是主体内容 </div> <div class="fix" id="back-to-top"> 返回顶部 </div> </body> <script src="jquery.js"></script> <script> $(function () { $(window).scroll(function () { if ($(window).scrollTop() > 100) { $("#back-to-top").fadeIn(1000); console.log($(window).scrollTop()) console.log(window.innerHeight) } else { $("#back-to-top").fadeOut(1000); } }); //当点击跳转链接后,回到页面顶部位置 $("#back-to-top").click(function () { $('body,html').animate({scrollTop: 0}, 1000); return false; }); }); </script> </html>
我写了小demo 明明就可以触发