<div class="wrap">
 <ul class="list">
  <li>
   <img src="img/img0.png">
  </li>
   <li>
   <img src="img/img1.png">
  </li>
 </ul>
 <a href="javascript:;" class="prev">prev</a>
 <a href="javascript:;" class="next">next</a>
</div>

(function(){
 var list=document.querySelector(".list");
 var imgs=document.querySelectorAll("img");
 var prev=document.querySelector(".prev");
 var next=document.querySelector(".next");
 var imgW=css(imgs[0],"width");//使用封裝好的css()獲取img的寬度
 var now=0;
 var imgData=["img/img0.png",
     "img/img1.png",
     "img/img2.png",
     "img/img3.png",];
 prev.onclick=function(){
  //找出接下來要顯示的圖片的下標
  var prev=(now-1+imgData.length)%imgData.length;
  //因為是從右往左運動，當前顯示的應在右側，即將顯示的在左側
  imgs[0].src=imgData[prev];
  imgs[1].src=imgData[now];
  //使用封裝好的css()設置list的位置
  css(list,"left",-imgW);
  //使用封裝好的運動函數來控制圖片移動
  startMove(list,{left:0},2000,"easeOut");
  now=prev;
 }
 next.onclick=function(){
  var next=(now+1)%imgData.length;
  imgs[0].src=imgData[now];
  imgs[1].src=imgData[next];
  css(list,"left",0);
  startMove(list,{left:-imgW},2000,"easeOut");
  now=next;
 }
})();

var isMove=false;//記錄定時器開關狀態(tài)
prev.onclick=function(){
 if(isMove){
  return;
 }
 ....上述上一張操作js代碼
 isMove=true;
 startMove(list,{left:-imgW},2000,"easeOut",function(){
  isMove=false; 
 });
}