无缝滚动实现一

结构

<div id="demo">
<div id="indemo">
<div id="demo1">
<a href="#"><img src="http://images.cnblogs.com/logo.jpg" /></a>
<a href="#"><img src="http://images.cnblogs.com/logo.jpg" /></a>
<a href="#"><img src="http://images.cnblogs.com/logo.jpg" /></a>
<a href="#"><img src="http://images.cnblogs.com/logo.jpg" /></a>
</div>
<div id="demo2"></div>
</div>
</div>

样式

左右样式
<style type="text/css">
<!--
#demo {
overflow:hidden;
border: 1px dashed #CCC;
width: 500px;
}
#demo img {
border: 3px solid #F2F2F2;
}
#indemo {
float: left;
width: 800%;
}
#demo1 {
float: left;
}
#demo2 {
float: left;
}
-->
</style>

上下样式
<style type="text/css">
<!--
#demo {
overflow:hidden;
border: 1px dashed #CCC;
height: 100px;
float: left;
}
#demo img {
border: 3px solid #F2F2F2;
display: block;
}
-->

行为

<script>
<!--
var speed=10;
var tab=document.getElementById("demo");
var tab1=document.getElementById("demo1");
var tab2=document.getElementById("demo2");
tab2.innerHTML=tab1.innerHTML;

//向左
function Marquee(){
if(tab2.offsetWidth-tab.scrollLeft<=0)
tab.scrollLeft-=tab1.offsetWidth
else{
tab.scrollLeft++;
}
}
//向右
function Marquee(){
if(tab.scrollLeft<=0)
tab.scrollLeft+=tab2.offsetWidth
else{
tab.scrollLeft--;
}
}
//向上
function Marquee(){
if(tab2.offsetTop-tab.scrollTop<=0)//当滚动至demo1与demo2交界时
tab.scrollTop-=tab1.offsetHeight //demo跳到最顶端
else{
tab.scrollTop++
}
}
//向下
function Marquee(){
if(tab1.offsetTop-tab.scrollTop>=0)//当滚动至demo1与demo2交界时
tab.scrollTop+=tab2.offsetHeight //demo跳到最顶端
else{
tab.scrollTop--
}
}

var MyMar=setInterval(Marquee,speed);
tab.onmouseover=function() {clearInterval(MyMar)};
tab.onmouseout=function() {MyMar=setInterval(Marquee,speed)};
-->
</script>