这是一款碰撞缓冲效果的导航条，JavaScript妙味课堂奉献给大家的作品，很不错的竖向菜单，希望大家喜欢。所用技术是JS和CSS。
运行效果截图如下：
在线演示地址如下：
具体代码如下：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <title>碰撞缓冲效果的导航条</title> <style type="text/css"> * { padding: 0; margin: 0; } li { list-style: none; } body { background: #fff; } ul { width: 202px; margin: 40px auto 0; position: relative; } li { width: 200px; height: 30px; line-height: 30px; padding-left: 10px; border: 1px solid #ccc; border-left: 3px solid #666; font-size: 14px; color: #333; margin-bottom: 5px; position: relative; z-index: 2; } a { color: #333; text-decoration: none; } .active { font-weight: bold; background: #fff0f0; } #bar { width: 10px; padding-left: 0; background: #cc6699; border: 1px solid #cc6699; position: absolute; top: 0; left: -14px; z-index: 3; } </style> <script> var obj = null; var aLis = null; var oBar = null; var iTime = null; var iSpeed = 0; var iAcc = 3; var onOff = 0; var iPrev = 0; var iNext = 0; function goTime() { for(var i = 0; i < aLis.length; i+=1) { if(aLis[i] === this) { var iTarget = (aLis[0].offsetHeight + 5) * i; iNext = i; onOff = iNext - iPrev; if(iTime) { clearInterval(iTime); } if(onOff>=0) { iTime = setInterval("elasticity("+ iTarget +")",35); } else { iTime = setInterval("postpone("+ iTarget +")",35); } iPrev = iNext; } aLis[i].className=""; this.className="active"; } } function elasticity(target) { var top = oBar.offsetTop; iSpeed+=iAcc; top += iSpeed; if(top >= target) { iSpeed*=-0.7; if(Math.abs(iSpeed)<=iAcc) { clearInterval(iTime); iTime=null; } top=target; } oBar.style.top = top + "px"; } function postpone(target) { if(oBar.offsetTop===target) { clearInterval(iTime); iTime=null; } else { iSpeed = (target - oBar.offsetTop)/4; oBar.style.top = oBar.offsetTop + iSpeed + "px"; } } window.onload = function(){ obj = document.getElementById("nav"); aLis = obj.getElementsByTagName("li"); oBar = document.getElementById("bar"); for(var i = 0; i < aLis.length; i+=1) { if(aLis[i].id!="bar") { aLis[i].onmouseover = goTime; } } }; </script> </head> <body> <ul> <li><a href="#">首页</a></li> <li><a href="#">脚本之家</a></li> <li><a href="#">妙味课程</a></li> <li><a href="#">联系方式</a></li> <li> </ul> </body> </html>