本文实例讲述了javascript实现的左右无缝滚动效果。分享给大家供大家参考，具体如下：
前面介绍过图片左右滚动，不过图片是间歇性的一张一张滚动，今天介绍的是几张图片一起进行无缝滚动，这是一个常用的 js 效果。
<!DOCTYPE HTML> <html lang="en-US"> <head> <meta charset="UTF-8"> <title>无缝滚动——左右</title> <link rel="stylesheet" type="text/css" href="../css/base.css" media="all"/> <style type="text/css"> #scroll{width:698px;height:108px;margin:50px auto 0;position:relative;overflow:hidden;} .btn_left{display:block;width:68px;height:68px;background:url(images/btn.jpg) no-repeat -70px -69px;position:absolute;top:20px;left:1px;z-index:1;} .btn_left:hover{background:url(images/btn.jpg) no-repeat -70px 0;} .btn_right{display:block;width:68px;height:68px;background:url(images/btn.jpg) no-repeat 1px -69px;position:absolute;top:20px;right:0;z-index:1;} .btn_right:hover{background:url(images/btn.jpg) no-repeat 1px 0;} #scroll .content{width:546px;height:108px;position:relative;overflow:hidden;margin:0 auto;} #scroll ul{position:absolute;} #scroll li{float:left;width:182px;height:108px;text-align:center;} #scroll li a:hover{position:relative;top:2px;} </style> </head> <body> <div id="scroll"> <a href="javascript:;"></a> <a href="javascript:;"></a> <div> <ul> <li><a href="#"><img src="images/1.jpg" width="178" height="108" alt=""/></a></li> <li><a href="#"><img src="images/2.jpg" width="178" height="108" alt=""/></a></li> <li><a href="#"><img src="images/3.jpg" width="178" height="108" alt=""/></a></li> <li><a href="#"><img src="images/4.jpg" width="178" height="108" alt=""/></a></li> </ul> </div> </div> </body> </html> <script type="text/javascript"> window.onload = function(){ var oDiv = document.getElementById('scroll'); var oUl = oDiv.getElementsByTagName('ul')[0]; var aLi = oDiv.getElementsByTagName('li'); var aBtn = oDiv.getElementsByTagName('a'); var speed = -1; var timer = null; oUl.innerHTML += oUl.innerHTML; oUl.style.width = aLi[0].offsetWidth * aLi.length + 'px'; timer = setInterval(function(){ oUl.style.left = oUl.offsetLeft + speed + 'px'; if(oUl.offsetLeft < - oUl.offsetWidth / 2){ oUl.style.left = '0'; }else if(oUl.offsetLeft > 0){ oUl.style.left = - oUl.offsetWidth / 2 + 'px'; } },30); aBtn[0].onclick = function(){ speed = -1; }; aBtn[1].onclick = function(){ speed = 1; }; oUl.onmouseover = function(){ clearInterval(timer); }; oUl.onmouseout = function(){ timer = setInterval(function(){ oUl.style.left = oUl.offsetLeft + speed + 'px'; if(oUl.offsetLeft < -oUl.offsetWidth / 2){ oUl.style.left = '0'; }else if(oUl.offsetLeft > 0){ oUl.style.left = - oUl.offsetWidth / 2 + 'px'; } },30); }; }; </script>
PS：如果想要改变移动速度，只需要改变 speed 的值。
希望本文所述对大家JavaScript程序设计有所帮助。