JS实现左右无缝轮播图完整代码示例

<!DOCTYPE html>
<html>
<head lang="en">
  <meta charset="UTF-8">
  <title>www.jb51.net JS左右无缝轮播</title>
  <style>
    * {margin:0;padding:0;}
    #scrollImg{width:1000px;margin:100px auto;}
    #prev{float:left;line-height:250px;}
    #next{float:right;line-height:250px;}
    #div1 {width:800px;height:250px;margin:0px auto;position:relative;overflow:hidden;}
    #div1 ul {position:absolute;left:0;top:0;}
    #div1 ul li {float:left;list-style:none;width:200px;height:250px;}
    #div1 ul li img{width:100%;height:100%;}
  </style>
</head>
<body>
<div id="scrollImg">
  <a href="javascript:void(0)" rel="external nofollow" rel="external nofollow" id="prev">向左</a>
  <a href="javascript:void(0)" rel="external nofollow" rel="external nofollow" id="next">向右</a>
  <div id="div1">
    <ul>
      <li><img src="image/0.jpeg" /></li>
      <li><img src="image/1.JPEG" /></li>
      <li><img src="image/3.jpg" /></li>
      <li><img src="image/4.jpeg" /></li>
    </ul>
  </div>
</div>
<script>
  window.onload=function(){
    var oDiv=document.getElementById("div1");
    var oUl=document.getElementsByTagName("ul")[0];
    var oLi=document.getElementsByTagName("li");
    var index=0;
    var timer;//定时器
    oUl.innerHTML=oUl.innerHTML+oUl.innerHTML;//将轮播内容复制一份
    oUl.style.width=oLi[0].offsetWidth*oLi.length+"px";
    //移动速度
    var speed=-10;
    //控制滚动的方向
    var prev=document.getElementById("prev");
    var next=document.getElementById("next");
    //上一页
    prev.onclick=function(){
      if(index==4){
        index=1;
        oUl.style.left="0px";
      }else{
        index++;
        speed=10;
      }
      move();
    };
    //下一页
    next.onclick=function(){
      if(index==0){
        index=3;
        oUl.style.left=-oUl.offsetWidth/2+"px";
      }else{
        index--;
        speed=-10;
      }
      move();
    };
    function move(){
      timer=setInterval(function () {
        oUl.style.left=oUl.offsetLeft-speed+"px";
        var stop=-index*oLi[0].offsetWidth+"px";
        prev.style.visibility="hidden";
        next.style.visibility="hidden";
        if(oUl.style.left==stop){
          clearInterval(timer);
          prev.style.visibility="visible";
          next.style.visibility="visible";
        }
      },20);
    }
  }
</script>
</body>
</html>