JavaScript实现仿hao123风格图片轮播特效

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>图片轮播</title>
 <style>
  .warp{
   width: 600px;
   height: 750px;
   position: relative;
   margin:30px auto 0;
   overflow: hidden;
  }
  #box{
   width: 600px;
   height: 750px;
   position: absolute;
   top: 0px;
   left: 0px;
   overflow: hidden;
   /*overflow-x:auto;*/
  }
  #box #con{
   width: 6000px;
   height: 750px;
   overflow: hidden;
  }
  #con img{
   float: left;
   width: 600px;
   height: 750px;
  }
  #btnL{
   position: absolute;
   left: 0px;
   top: 366px;
   width: 36px;
   height: 36px;
   background: url(images/btnL.png) 0 0 no-repeat;
   cursor: pointer;
  }
  #btnR{
   position: absolute;
   right: 0px;
   top: 366px;
   width: 36px;
   height: 36px;
   background: url(images/btnR.png) 0 0 no-repeat;
   cursor: pointer;
  }
  #num{
   position: absolute;
   bottom: 10px;
   left: 148px;
   overflow: hidden;
   list-style: none;
  }
  #num li{
   float: left;
   margin:0 5px;
   font-size: 16px;
   line-height: 25px;
   height: 25px;
   width: 25px;
   background: #ccc;
   text-align: center;
   cursor: pointer;
  }
  #num li.select{
   background-color: green;
   color: white;
  }
 </style>
</head>
<body>
 <div class="warp">
  <div id="box">
   <div id="con">
    <img src="images/meinv1.jpg" alt="">
    <img src="images/meinv2.jpg" alt="">
    <img src="images/meinv3.jpg" alt="">
    <img src="images/meinv4.jpg" alt="">
    <img src="images/meinv5.jpg" alt="">
    <img src="images/meinv6.jpg" alt="">
   </div>
  </div>
  <div id="btnL"></div>
  <div id="btnR"></div>
  <ul id="num">
   <li class="select">1</li>
   <li>2</li>
   <li>3</li>
   <li>4</li>
   <li>5</li>
   <li>6</li>
  </ul>
 </div>
 <script>
  var box=document.getElementById('box');
  var con=document.getElementById('con');
  var imgs=con.getElementsByTagName('img');
  var btnL=document.getElementById('btnL');
  var btnR=document.getElementById('btnR');
  var num=document.getElementById('num');
  var lis=num.getElementsByTagName('li');
  var timer1=null,timer2=null;
  var imgw=imgs[0].clientWidth;
  var x=0;
  function imgScroll(){//图片切换
   var start=box.scrollLeft;
   var end=imgw*x;
   var change=end-start;
   var minstep=0;
   var maxstep=30;
   var stepLength=change/maxstep;
    clearInterval(timer2);
    timer2=setInterval(function(){
     minstep++;
     // console.log(minstep);
     if (minstep>=maxstep) {
      clearInterval(timer2);
     }
     start+=stepLength;
     box.scrollLeft=start;
    },20) 
    for (var i = 0; i < lis.length; i++) {
     lis[i].className='none';
    }
    lis[x].className='select';
  }
  function move(){//默认向左每隔3s滚动
   clearInterval(timer1);
   timer1=setInterval(function(){
    x++;
    if (x>=imgs.length) {
     x=0;
    }
    imgScroll();
    for (var i = 0; i < lis.length; i++) {
     lis[i].className='none';
     lis[x].className='select';
    }
    },3000);
   }
  move();//启动默认滚动函数；
  btnR.onclick=function(){
   clearInterval(timer1);
   x++;
   if (x>=imgs.length) {
    x=0;
   }
   imgScroll();
   move();
  }
  btnL.onclick=function(){
   clearInterval(timer1);
   x--;
   if (x<0) {
    x=imgs.length-1;
   }
   imgScroll();
   move();
  }
  for (var i = 0; i < lis.length; i++) {
   lis[i].index=i;
   lis[i].onclick=function(){
    x=this.index;
    imgScroll();
    move();
   }
  }

 </script>
</body>
</html>