下面是整体代码 复制即可使用,
<!DOCTYPE html> <html lang="zn"> <head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>网页轮播图案例</title> <script> window.addEventListener('load', function () { var box = document.querySelector('.box'); var right = box.querySelector('.right'); var left = box.querySelector('.left'); var ul = box.querySelector('ul'); var ul_lis = ul.querySelectorAll('li'); var ol = box.querySelector('ol'); var num = 0; var circle = 0; var flag = true; // 1.鼠标经过轮播图模块, 左右按钮显示, 离开隐藏左右按钮。 box.addEventListener('mouseenter', function () { right.style.display = 'block'; left.style.display = 'block'; clearInterval(timer); timer = null; }); box.addEventListener('mouseleave', function () { right.style.display = 'none'; left.style.display = 'none'; timer = setInterval(function () { right.click(); }, 2000); }); var timer = setInterval(function () { right.click(); }, 2000); //2.动态生成小圆圈 for (var i = 0; i < ul_lis.length; i++) { var li = document.createElement('li'); li.className = 'current'; li.setAttribute('index', i); ol.appendChild(li); //添加注册事件 排他思想 li.addEventListener('click', function () { for (var i = 0; i < ol.children.length; i++) { ul_lis[i].style.opacity = '0';//排他思想:全部图片设置为透明 ol.children[i].className = 'current'; } this.className = 'current white'; var index = this.getAttribute('index'); ul_lis[index].style.opacity = '1';//留下需要显示的图片 num = index; circle = index; }); } ol.children[0].className = 'current white'; //TRUE 深拷贝 复制内容且复制标签 var first = ul.children[0].cloneNode(true); ul.appendChild(first); // 2.点击右侧按钮一 次, 图片往左播放一张, 以此类推, 左侧按钮同理。 right.addEventListener('click', function () { if (flag) { flag = false; if (num == ul.children.length - 1) { num = 0; } num++; if (num == 4) { num = 0; } for (var i = 0; i < ol.children.length; i++) { ul_lis[i].style.opacity = '0'; } ul_lis[num].style.opacity = '1'; flag = true; //变量控制小圆圈的变化 circle++; if (circle == ol.children.length) { circle = 0; } circlechange(); } }); function circlechange() { for (var i = 0; i < ol.children.length; i++) { ol.children[i].className = 'current'; } ol.children[circle].className = 'current white'; }; left.addEventListener('click', function () { if (flag) { flag = false; //实现无缝滚动 if (num == 0) { num = ul.children.length - 1; } num--; if (num == -1) { num = 4; } for (var i = 0; i < ol.children.length; i++) { ul_lis[i].style.opacity = '0'; } ul_lis[num].style.opacity = '1'; flag = true;//一次只执行完毕才可以点击下一次 //变量控制小圆圈的变化 circle--; if (circle < 0) { circle = ol.children.length - 1; } circlechange(); } }); }); </script> <style> * { margin: 0px; padding: 0px; list-style: none; } .box { position: relative; width: 810px; height: 540px; left: 50%; transform: translateX(-50%); } img { width: 810px; height: 540px; } ul li { position: absolute; top: 0px; left: 0px; opacity: 0; transition: 1s; } ul li:first-child { opacity: 1; } ul { width: 100%; position: absolute; top: 0px; left: 0px; } span { width: 20px; height: 40px; font-size: 25px; line-height: 40px; display: block; position: absolute; color: black; background-color: #ccc; opacity: .5; text-align: center; top: 50%; transform: translateY(-50%); cursor: pointer; display: none; } .right { right: 0px; } .left { left: 0px; } ol { position: absolute; left: 50%; z-index: 999; transform: translateX(-50%); bottom: 5px; } .current { float: left; display: block; width: 25px; height: 5px; background-color: rgb(41, 39, 39); margin-right: 10px; opacity: 0.5; } .white { background-color: #fff; } </style> </head> <body> <div class="box"> <ul> <li> <img src="../img/1.jpg" alt=""> </li> <li> <img src="../img/2.jpg" alt=""> </li> <li> <img src="../img/3.jpg" alt=""> </li> <li> <img src="../img/4.jpg" alt=""> </li> </ul> <span class="right"> > </span> <span class="left"> < </span> <ol> </ol> </div> </body> </html>
常见的轮播图有两种:移动距离轮播图,渐变切换轮播图但是轮播图的代码都是差不太多的。这里就是给大家讲解的是渐变轮播图的切换,
这个是对轮播图的上下左右进行隐藏
box(装整个轮播图的盒子)获得焦点的时候按钮style.display属性改为block失去焦点none。
//获取焦点显示 box.addEventListener('mouseenter', function () { right.style.display = 'block'; left.style.display = 'block'; }); //失去焦点隐藏 box.addEventListener('mouseleave', function () { right.style.display = 'none'; left.style.display = 'none'; });
添加圆点
图片的数量动态生成小圆圈的数量,实现灵活控制。根据ul里的li的长度得到小圆圈的数量。
for (var i = 0; i < ul_lis.length; i++) { var li = document.createElement('li'); li.className = 'current';//current类是样式 ol.appendChild(li); //添加注册事件 排他思想 li.addEventListener('click', function () { for (var i = 0; i < ol.children.length; i++) { ol.children[i].className = 'current'; } this.className = 'current white'; var index = this.getAttribute('index'); num = index; circle = index; }); } ol.children[0].className = 'current white';//默认第一个为白色底
给左右添加
给ol添加一个index属性,以便于获取当前属于第几张图片(ol 和 ul 里面的 li 数量是一致的)。给左按钮添加一个点击事件,根据num(num由index赋值过来)跳转下一张图;设置flag(节流阀)保证是一次跳转完成之后才可以实现下一次的跳转。
//TRUE 深拷贝 复制内容且复制标签 var first = ul.children[0].cloneNode(true); ul.appendChild(first); // 2.点击右侧按钮一 次, 图片往左播放一张, 以此类推, 左侧按钮同理。 right.addEventListener('click', function () { if (flag) { flag = false; if (num == ul.children.length - 1) { num = 0; } num++; if (num == 4) { num = 0; } for (var i = 0; i < ol.children.length; i++) { ul_lis[i].style.opacity = '0'; } ul_lis[num].style.opacity = '1'; flag = true; //变量控制小圆圈的变化 circle++; if (circle == ol.children.length) { circle = 0; } circlechange(); } }); left.addEventListener('click', function () { if (flag) { flag = false; //实现无缝滚动 if (num == 0) { num = ul.children.length - 1; } num--; if (num == -1) { num = 4; } for (var i = 0; i < ol.children.length; i++) { ul_lis[i].style.opacity = '0'; } ul_lis[num].style.opacity = '1'; flag = true;//一次只执行完毕才可以点击下一次 //变量控制小圆圈的变化 circle--; if (circle < 0) { circle = ol.children.length - 1; } circlechange(); } }); }); function circlechange() { for (var i = 0; i < ol.children.length; i++) { ol.children[i].className = 'current'; } ol.children[circle].className = 'current white'; };
最后一步就是 实现自动轮播啦
box.addEventListener('mouseenter', function () { clearInterval(timer); timer = null; }); box.addEventListener('mouseleave', function () { timer = setInterval(function () { right.click(); }, 2000); }); var timer = setInterval(function () { right.click(); }, 2000);