js实现简单的轮播图效果

本文实例为大家分享了js实现简单的轮播图效果的具体代码，供大家参考，具体内容如下

代码：

<!DOCTYPE html>
<html>

<head>
 <meta charset="utf-8" />
 <title></title>
 <link rel="stylesheet" type="text/css" href="css/style.css" />
 <style>
 * {
 margin: 0;
 padding: 0;
 }

 .box {
 width: 100%;
 height: 500px;
 border: 1px solid;
 }
 </style>
 <script src="./js/new_file.js"></script>
</head>

<body>
 <div class="box_1">
 <div class="c-banner">
 <div class="banner">
 <ul id="banner">
  <li><img src="img/su_ning1.png"></li>
  <li><img src="img/su_ning2.png"></li>
  <li><img src="img/su_ning3.png"></li>
  <li><img src="img/su_ning4.png"></li>
  <li><img src="img/su_ning5.png"></li>
  <li><img src="img/su_ning6.png"></li>
  <li><img src="img/su_ning7.png"></li>
  <li><img src="img/su_ning8.png"></li>
 </ul>
 </div>
 <div class="nexImg" id="nexImg">
 <img src="img/nexImg.png" />
 </div>
 <div class="preImg" id="preImg">
 <img src="img/preImg.png" />
 </div>
 <div class="jumpBtn">
 <ul id="jumpBtn">
  <li></li>
  <li></li>
  <li></li>
  <li></li>
  <li></li>
  <li></li>
  <li></li>
 </ul>
 </div>
 </div>
</body>

</html>

js:

window.onload = function() {
 //banner 自动播放
 var oBanner = document.getElementById('banner');
 var aLi = oBanner.getElementsByTagName('li');
 var oJumpBtn = document.getElementById('jumpBtn');
 var aBtn = oJumpBtn.getElementsByTagName('li');
 var oPreImg = document.getElementById('preImg');
 var oNexImg = document.getElementById('nexImg');
 var iNow = 0;
 var timer = null;
 for (var i = 0; i < aBtn.length; i++) {
 aBtn[i].index = i;
 aBtn[i].onclick = function() {
 iNow = this.index;
 tab();
 };
 }

 function tab() {
 for (var i = 0; i < aBtn.length; i++) {
 aBtn[i].style.background = '#ccc';
 aLi[i].style.opacity = 0;
 }
 aBtn[iNow].style.background = '#CF0F32';
 aLi[iNow].style.opacity = 1;
 }

 function tick() {
 iNow++;
 if (iNow == aBtn.length) {
 iNow = 0;
 }
 tab();
 }

 timer = setInterval(tick, 2000);

 oPreImg.onclick = function() {
 iNow--;
 if (iNow < 0) {
 iNow = aBtn.length - 1;
 }
 tab();
 };
 oNexImg.onclick = tick;

 oBanner.onmouseover = function() {
 clearInterval(timer);
 };
 oBanner.onmouseout = function() {
 timer = setInterval(tick, 2000);
 };
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。