代码如下：
<!doctype html> <html> <head> <meta charset="UTF-8"> <title>Title</title> <style> *{margin:0; padding:0; list-style:none;} ul{ overflow:hidden; background:#ccc; width:574px; margin:100px auto; position:relative;} ul li{ float:left; width:80px; height:40px; text-align:center; line-height:40px; border:1px solid #000; position:relative; z-index:2;} #block_box{ position:absolute; top:0; left:0; background:#399; z-index:1;} </style> <script> var left = 0; var iSpeed = 0; function move(obj,iTarget){ clearInterval(obj.timer); obj.timer = setInterval(function(){ iSpeed+=(iTarget-left)/5; iSpeed*=0.75; left+=iSpeed; obj.style.left = left+'px'; if(Math.round(iSpeed)==0&&Math.round(left)==iTarget){ clearInterval(obj.timer); } },30); } window.onload = function(){ var aLi = document.getElementsByTagName('li'); var oBlock = document.getElementById('block_box'); var iNow = 0; for(var i=0;i<aLi.length-1;i++){ ;(function(index){ aLi[i].onmouseover = function(){ //oBlock.style.left = index*aLi[0].offsetWidth+'px'; move(oBlock,index*aLi[0].offsetWidth); }; aLi[i].onmouseout = function(){ //oBlock.style.left = 0; move(oBlock,iNow*aLi[0].offsetWidth); }; aLi[i].onclick = function(){ iNow=index; }; })(i); } }; </script> </head> <body> <ul> <li>首页</li> <li>CSS课程</li> <li>JS课程</li> <li>HTML5课程</li> <li>视频教程</li> <li>课程案例</li> <li>联系方式</li> <li></li> </ul> </body> </html>