js无缝滚动效果几乎在任何网页上都能看到它的身影，有的可能是使用插件，其实使用原始的javascript比较简单。
主要的是使用js位置知识。
1.innerHTML:设置或获取元素的html标签
2.scrollLeft:设置或获取位于对象左边界和窗口中目前可见内容的最左端之间的距
3.offsetWidth:设置或获取指定标签的宽度
4.setInterval():设置方法定时启动
5.clearInterval();清除定时器
效果图：
先睹为快：demo
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>javascript scroll制作</title>
</head>
<body>
<style>
/*conment*/
*{
margin: 0;
padding: 0;
}
img{max- 100%;}
.container{
max- 620px;
margin: 0 auto;
padding-top: 50px;
}
.text-center{text-align: center;}
.list-inline li{
display: inline-block;
}
.hide{display: none;}
hr{
margin:20px 0;
}
.tag{
background-color: #ccc;
padding: 5px 0;
}
.tag li{
padding: 0 10px;
border-left: 1px solid #fff;
cursor:pointer;
}
.tag li:first-child{
border-left: transparent;
}
.tag li.active{
background-color: #ddd;
}
.scroll{
position: relative;
padding: 10px;
margin-bottom: 20px;
background-color: #ddd;
}
.wrap{
overflow: hidden;
}
.content{
min- 3000px;
height: 200px;
}
.content ul{
float: left;
}
.content ul li{
display: inline-block;
max- 200px;
}
#prev,#next{
50px;
height: 50px;
margin-top: -25px;
background-color: #ccc;
line-height: 50px;
text-align: center;
cursor: pointer;
}
#prev{
position: absolute;
left: 0;
top:50%;
border-radius: 0 25px 25px 0;
}
#next{
position: absolute;
right: 0;
top:50%;
border-radius: 25px 0 0 25px;
}
</style>
<div class="container">
<h1 class="text-center">图片滚动制作</h1>
<hr>
<div class="scroll">
<div class="wrap" id="wrap">
<div id="content" class="content" >
<ul id="list1">
<li> <img src="freelance.gif" alt=""> </li>
<li> <img src="button.gif" alt=""></li>
<li> <img src="load.gif" alt=""></li>
<li> <img src="straw.gif" alt=""></li>
</ul>
<ul id="list2">
</ul>
</div>
</div>
<div id="prev">
prev
</div>
<div id="next">
next
</div>
</div>
</div>
<script>
var wrap=document.getElementById('wrap');
var list1=document.getElementById('list1');
var list2=document.getElementById('list2');
var prev=document.getElementById('prev');
var next=document.getElementById('next');
//创建复制一份内容列表
list2.innerHTML=list1.innerHTML;
//向左循环滚动
function scroll(){
if(wrap.scrollLeft>=list2.offsetWidth){
wrap.scrollLeft=0;
}
else{
wrap.scrollLeft++;
}
}
timer = setInterval(scroll,1);
//鼠标停留使用clearInterval()
wrap.onmouseover=function(){
clearInterval(timer);
}
wrap.onmouseout=function(){
timer = setInterval(scroll,1);
}
//向左加速
function scroll_l(){
if(wrap.scrollLeft>=list2.offsetWidth){
wrap.scrollLeft=0;
}
else{
wrap.scrollLeft++;
}
}
//向右滚动
function scroll_r(){
if(wrap.scrollLeft<=0){
wrap.scrollLeft+=list2.offsetWidth;
}
else{
wrap.scrollLeft--;
}
}
prev.onclick=function(){
clearInterval(timer);
change(0)
}
next.onclick=function(){
clearInterval(timer);
change(1)
}
function change(r){
if(r==0){
timer = setInterval(scroll_l,60);
wrap.onmouseout = function(){
timer = setInterval(scroll_l,60);
}
}
if(r==1){
timer = setInterval(scroll_r,60);
wrap.onmouseout = function(){
timer = setInterval(scroll_r,60);
}
}
}
</script>
</body>
</html>