JS实现无限轮播无倒退效果

<div class="slide-container" view-count="3">
 <ul>
 <li>
  <img src="images/women/15444293310974910.jpg" alt=""/>
 </li>
 <li>
  <img src="images/women/15444293312083674.jpg" alt=""/>
 </li>
 <li>
  <img src="images/women/15444293313734437.jpg" alt=""/>
 </li>
 <li>
  <img src="images/women/15444293315979953.jpg" alt=""/>
 </li>
 <li>
  <img src="images/women/15444293316955485.jpg" alt=""/>
 </li>
 <li>
  <img src="images/women/15444293317767707.jpg" alt=""/>
 </li>
 </ul>
</div>

.slide-container {
  max-width: 1230px;
  margin: auto;
  overflow: hidden;
 }
 .slide-container li {
  float: left;
 }
 .slide-container img {
  width: 100%;
 }

let orgLen, canMove, curLi, curLen,
  slider = null,
  interval = null,
  curImgIndex = 0;
 
 function initSlider() {
  let orgLiArray = document.querySelectorAll('.slide-container li');
 
  orgLen = orgLiArray.length;
  canMove = true;
  slider = $('.slide-container');
 
  addLi();
  setStyle();
 
  //添加li
  function addLi() {
  for (let i = 0; i < orgLen; i++) {
   let preLi = orgLiArray[orgLen - i - 1].cloneNode(true);
   let apLi = orgLiArray[i].cloneNode(true);
   document.querySelector('.slide-container ul').prepend(preLi);
   document.querySelector('.slide-container ul').append(apLi);
  }
  }
 
  function setStyle() {
  curLi = slider.find('li');
  curLen = curLi.length;
 
  curLi.css({
   'width': 'calc(' + 100 / curLen + '% - 10px)', //动态设置li的宽度
   'margin': '0 5px'
  });
 
  //根据实际li个数与ul中用户能够看到的个数比例设置ul宽度
  slider.find('ul').css({
   'width': curLen / slider.attr('view-count') * 100 + '%', 
  });
 
  //获取到设置了width之后的li宽度
  //通过margin-left 与margin-right 为负数 使中间的原始li集合在slide-container显示
  let width = document.defaultView.getComputedStyle(curLi[0]).width.match(/\d*\W\d/g);
 
  width = (parseFloat(width) + 10) * orgLen;
  slider.find('ul').css({
   'margin-left': '-' + width + 'px',
   'margin-right': '-' + width + 'px',
  });
  }
 } 
 
 /**
  * 移动函数
  * 每次移动后移除过渡效果
  * 当前第一个图片索引值的绝对值大于原始图片数量则恢复为原始状态
  * @param imgIndex
  */
 function move(imgIndex) {
  canMove = false; //滚轮滚动中不能再次滚动
  clearInterval(interval); //清除定时器
  slider.find('ul').css({
  'transition': 'all 0.5s linear'
  });
 
  setTimeout(function () { //移动
  slider.find('ul').css({
   'transform': 'translateX( ' + 100 / curLen * -imgIndex + '% )',
  });
  setTimeout(function () { //移动完成后清除过渡效果
   slider.find('ul').css({
   'transition': '',
   });
   setTimeout(function () {
   if (Math.abs(imgIndex) >= orgLen) { //到达边界回到初始状态
    curImgIndex = 0;
    slider.find('ul').css({
    'transform': 'translateX(0)'
    });
   }
   canMove = true;
   startInterval();
   }, 20);
  }, 500);
  }, 20);
 }
 
 function startInterval() {
  interval = setInterval(function () { //开始轮播
  curImgIndex++;
  move(curImgIndex);
  },2000);
 }
 
 initSlider();
 startInterval();

//统一处理滚轮滚动事件
 function wheel(event) {
  var delta = 0;
  if (!event) event = window.event;
  if (event.wheelDelta) { //IE、chrome浏览器使用的是wheelDelta，并且值为“正负120”
  delta = event.wheelDelta / 120;
  if (window.opera)
 
  //因为IE、chrome等向下滚动是负值，FF是正值，为了处理一致性，在此取反处理
   delta = -delta;
  } else if (event.detail) { //FF浏览器使用的是detail,其值为“正负3”
  delta = -event.detail / 3;
  }
  if (delta) {
  handle(delta);
 
  //阻止事件冒泡和屏幕向下滚动
  event.preventDefault() && event.stopPropagation();
  }
 
 }
 
 //上下滚动时的具体处理函数
 function handle(delta) {
  //向上滚动
  if (delta < 0 && canMove) {
  curImgIndex++;
  move(curImgIndex);
  } else if (delta > 0 && canMove) { //向下滚动
  curImgIndex--;
  move(curImgIndex);
  }
 }

//兼容性写法
if (window.addEventListener) //FF,火狐浏览器会识别该方法
 slider.get(0).addEventListener('DOMMouseScroll', wheel, false);
 slider.get(0).onmousewheel = wheel; //W3C