Posted in Javascript onApril 04, 2019
本文实例讲述了JS实现图片轮播效果。分享给大家供大家参考,具体如下:
本次轮播效果图如下:
具有以下功能:1.自动播放(鼠标进入显示区域时停止播放) 2.左右焦点切换 3.底下小按钮切换
以下为实现代码:
首先是html代码:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>最简单的轮播效果</title> </head> <body> <div class="box" id="box"> <div class="inner"> <!--轮播图--> <ul> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="images/1.jpg" alt=""></a></li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="images/2.jpg" alt=""></a></li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="images/3.jpg" alt=""></a></li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="images/4.jpg" alt=""></a></li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="images/5.jpg" alt=""></a></li> </ul> <ol class="bar"> 小按钮数量无法确定,由js动态生成 </ol> <!--左右焦点--> <div id="arr"> <span id="left"> <</span> <span id="right">></span> </div> </div> </div> </body> </html>
接下来是css样式:
<style> * { margin: 0; padding: 0 } .box { width: 500px; height: 300px; border: 1px solid #ccc; margin: 100px auto; padding: 5px; } .inner{ width: 500px; height: 300px; position: relative; overflow: hidden; } .inner img{ width: 500px; height: 300px; vertical-align: top } ul { width: 1000%; position: absolute; list-style: none; left:0; top: 0; } .inner li{ float: left; } ol { position: absolute; height: 20px; right: 20px; bottom: 20px; text-align: center; padding: 5px; } ol li{ display: inline-block; width: 20px; height: 20px; line-height: 20px; background-color: #fff; margin: 5px; cursor: pointer; } ol .current{ background-color: red; } #arr{ display: none; } #arr span{ width: 40px; height: 40px; position: absolute; left: 5px; top: 50%; margin-top: -20px; background: #fff; cursor: pointer; line-height: 40px; text-align: center; font-weight: bold; font-family: '黑体'; font-size: 30px; color: #000; opacity: 0.5; border: 1px solid #fff; } #arr #right { right: 5px; left: auto; }
第三部分是最主要的js代码:
<script> /** * * @param id 传入元素的id * @returns {HTMLElement | null} 返回标签对象,方便获取元素 */ function my$(id) { return document.getElementById(id); } //获取各元素,方便操作 var box=my$("box"); var inner=box.children[0]; var ulObj=inner.children[0]; var list=ulObj.children; var olObj=inner.children[1]; var arr=my$("arr"); var imgWidth=inner.offsetWidth; var right=my$("right"); var pic=0; //根据li个数,创建小按钮 for(var i=0;i<list.length;i++){ var liObj=document.createElement("li"); olObj.appendChild(liObj); liObj.innerText=(i+1); liObj.setAttribute("index",i); //为按钮注册mouseover事件 liObj.onmouseover=function () { //先清除所有按钮的样式 for (var j=0;j<olObj.children.length;j++){ olObj.children[j].removeAttribute("class"); } this.className="current"; pic=this.getAttribute("index"); animate(ulObj,-pic*imgWidth); } } //设置ol中第一个li有背景颜色 olObj.children[0].className = "current"; //克隆一个ul中第一个li,加入到ul中的最后=====克隆 ulObj.appendChild(ulObj.children[0].cloneNode(true)); var timeId=setInterval(onmouseclickHandle,1000); //左右焦点实现点击切换图片功能 box.onmouseover=function () { arr.style.display="block"; clearInterval(timeId); }; box.onmouseout=function () { arr.style.display="none"; timeId=setInterval(onmouseclickHandle,1000); }; right.onclick=onmouseclickHandle; function onmouseclickHandle() { //如果pic的值是5,恰巧是ul中li的个数-1的值,此时页面显示第六个图片,而用户会认为这是第一个图, //所以,如果用户再次点击按钮,用户应该看到第二个图片 if (pic == list.length - 1) { //如何从第6个图,跳转到第一个图 pic = 0;//先设置pic=0 ulObj.style.left = 0 + "px";//把ul的位置还原成开始的默认位置 } pic++;//立刻设置pic加1,那么此时用户就会看到第二个图片了 animate(ulObj, -pic * imgWidth);//pic从0的值加1之后,pic的值是1,然后ul移动出去一个图片 //如果pic==5说明,此时显示第6个图(内容是第一张图片),第一个小按钮有颜色, if (pic == list.length - 1) { //第五个按钮颜色干掉 olObj.children[olObj.children.length - 1].className = ""; //第一个按钮颜色设置上 olObj.children[0].className = "current"; } else { //干掉所有的小按钮的背景颜色 for (var i = 0; i < olObj.children.length; i++) { olObj.children[i].removeAttribute("class"); } olObj.children[pic].className = "current"; } } left.onclick=function () { if (pic==0){ pic=list.length-1; ulObj.style.left=-pic*imgWidth+"px"; } pic--; animate(ulObj,-pic*imgWidth); for (var i = 0; i < olObj.children.length; i++) { olObj.children[i].removeAttribute("class"); } //当前的pic索引对应的按钮设置颜色 olObj.children[pic].className = "current"; }; //设置任意的一个元素,移动到指定的目标位置 function animate(element, target) { clearInterval(element.timeId); //定时器的id值存储到对象的一个属性中 element.timeId = setInterval(function () { //获取元素的当前的位置,数字类型 var current = element.offsetLeft; //每次移动的距离 var step = 10; step = current < target ? step : -step; //当前移动到位置 current += step; if (Math.abs(current - target) > Math.abs(step)) { element.style.left = current + "px"; } else { //清理定时器 clearInterval(element.timeId); //直接到达目标 element.style.left = target + "px"; } }, 10); } </script>
所有用图片如下:
1.jpg
2.jpg
3.jpg
4.jpg
5.jpg
下面是完整的代码:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>最简单的轮播效果</title> <style> * { margin: 0; padding: 0 } .box { width: 500px; height: 300px; border: 1px solid #ccc; margin: 100px auto; padding: 5px; } .inner{ width: 500px; height: 300px; position: relative; overflow: hidden; } .inner img{ width: 500px; height: 300px; vertical-align: top } ul { width: 1000%; position: absolute; list-style: none; left:0; top: 0; } .inner li{ float: left; } ol { position: absolute; height: 20px; right: 20px; bottom: 20px; text-align: center; padding: 5px; } ol li{ display: inline-block; width: 20px; height: 20px; line-height: 20px; background-color: #fff; margin: 5px; cursor: pointer; } ol .current{ background-color: red; } #arr{ display: none; } #arr span{ width: 40px; height: 40px; position: absolute; left: 5px; top: 50%; margin-top: -20px; background: #fff; cursor: pointer; line-height: 40px; text-align: center; font-weight: bold; font-family: '黑体'; font-size: 30px; color: #000; opacity: 0.5; border: 1px solid #fff; } #arr #right { right: 5px; left: auto; } </style> </head> <body> <div class="box" id="box"> <div class="inner"> <!--轮播图--> <ul> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="images/1.jpg" alt=""></a></li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="images/2.jpg" alt=""></a></li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="images/3.jpg" alt=""></a></li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="images/4.jpg" alt=""></a></li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="images/5.jpg" alt=""></a></li> </ul> <ol class="bar"> </ol> <!--左右焦点--> <div id="arr"> <span id="left"> < </span> <span id="right"> > </span> </div> </div> </div> <script> /** * * @param id 传入元素的id * @returns {HTMLElement | null} 返回标签对象,方便获取元素 */ function my$(id) { return document.getElementById(id); } //获取各元素,方便操作 var box=my$("box"); var inner=box.children[0]; var ulObj=inner.children[0]; var list=ulObj.children; var olObj=inner.children[1]; var arr=my$("arr"); var imgWidth=inner.offsetWidth; var right=my$("right"); var pic=0; //根据li个数,创建小按钮 for(var i=0;i<list.length;i++){ var liObj=document.createElement("li"); olObj.appendChild(liObj); liObj.innerText=(i+1); liObj.setAttribute("index",i); //为按钮注册mouseover事件 liObj.onmouseover=function () { //先清除所有按钮的样式 for (var j=0;j<olObj.children.length;j++){ olObj.children[j].removeAttribute("class"); } this.className="current"; pic=this.getAttribute("index"); animate(ulObj,-pic*imgWidth); } } //设置ol中第一个li有背景颜色 olObj.children[0].className = "current"; //克隆一个ul中第一个li,加入到ul中的最后=====克隆 ulObj.appendChild(ulObj.children[0].cloneNode(true)); var timeId=setInterval(onmouseclickHandle,1000); //左右焦点实现点击切换图片功能 box.onmouseover=function () { arr.style.display="block"; clearInterval(timeId); }; box.onmouseout=function () { arr.style.display="none"; timeId=setInterval(onmouseclickHandle,1000); }; right.onclick=onmouseclickHandle; function onmouseclickHandle() { //如果pic的值是5,恰巧是ul中li的个数-1的值,此时页面显示第六个图片,而用户会认为这是第一个图, //所以,如果用户再次点击按钮,用户应该看到第二个图片 if (pic == list.length - 1) { //如何从第6个图,跳转到第一个图 pic = 0;//先设置pic=0 ulObj.style.left = 0 + "px";//把ul的位置还原成开始的默认位置 } pic++;//立刻设置pic加1,那么此时用户就会看到第二个图片了 animate(ulObj, -pic * imgWidth);//pic从0的值加1之后,pic的值是1,然后ul移动出去一个图片 //如果pic==5说明,此时显示第6个图(内容是第一张图片),第一个小按钮有颜色, if (pic == list.length - 1) { //第五个按钮颜色干掉 olObj.children[olObj.children.length - 1].className = ""; //第一个按钮颜色设置上 olObj.children[0].className = "current"; } else { //干掉所有的小按钮的背景颜色 for (var i = 0; i < olObj.children.length; i++) { olObj.children[i].removeAttribute("class"); } olObj.children[pic].className = "current"; } } left.onclick=function () { if (pic==0){ pic=list.length-1; ulObj.style.left=-pic*imgWidth+"px"; } pic--; animate(ulObj,-pic*imgWidth); for (var i = 0; i < olObj.children.length; i++) { olObj.children[i].removeAttribute("class"); } //当前的pic索引对应的按钮设置颜色 olObj.children[pic].className = "current"; }; //设置任意的一个元素,移动到指定的目标位置 function animate(element, target) { clearInterval(element.timeId); //定时器的id值存储到对象的一个属性中 element.timeId = setInterval(function () { //获取元素的当前的位置,数字类型 var current = element.offsetLeft; //每次移动的距离 var step = 10; step = current < target ? step : -step; //当前移动到位置 current += step; if (Math.abs(current - target) > Math.abs(step)) { element.style.left = current + "px"; } else { //清理定时器 clearInterval(element.timeId); //直接到达目标 element.style.left = target + "px"; } }, 10); } </script> </body> </html>
希望本文所述对大家JavaScript程序设计有所帮助。
JS实现图片轮播效果实例详解【可自动和手动】
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