輪播圖也稱爲焦點圖,是網頁中比較常見的網頁特效。
功能需求:
1.鼠標經過輪播圖模塊,左右按鈕顯示,離開隱藏左右按鈕。
2.點擊右側按鈕一次,圖片往左播放一張,以此類推,左側按鈕同理。
3.圖片播放的同時,下面小圓圈模塊跟隨一起變化。
4.點擊小圓圈,可以播放相應圖片。
5.鼠標不經過輪播圖,輪播圖也會自動播放圖片。
6.鼠標經過,輪播圖模塊, 自動播放停止。
此文章的代碼爲一個完整的輪播圖的實現代碼,複製即可運行
實現效果由於大小問題無法上傳,可自行觀看淘寶或京東首頁輪播圖效果
html文件:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<link rel="stylesheet" href="css/index.css">
<script src="js/animate.js"></script>
<script src="js/index.js"></script>
</head>
<body>
<div class="box">
<ul>
<li><img src="img/focus.jpg" alt=""></li>
<li><img src="img/focus1.jpg" alt=""></li>
<li><img src="img/focus2.jpg" alt=""></li>
<li><img src="img/focus3.jpg" alt=""></li>
</ul>
<ol>
</ol>
<div class="arr-l"> < </div>
<div class="arr-r"> > </div>
</div>
</body>
</html>
css文件:
* {
margin: 0;
padding: 0;
outline: none;
}
.box {
overflow: hidden;
position: relative;
height: 455px;
width: 721px;
background-color: pink;
margin: 50px auto;
}
.box ul {
position: absolute;
top: 0;
left: 0;
width: 600%;
}
.box ul li {
list-style: none;
float: left;
}
.box ol {
position: absolute;
bottom: 10px;
left: 100px;
background-color: rgba(255, 255, 255, .3);
border-radius: 8px;
list-style: none;
height: 10px;
padding: 2px 5px;
}
.box ol li {
cursor: pointer;
float: left;
height: 8px;
width: 8px;
border: 1px solid #fff;
border-radius: 50%;
margin: 0 5px;
}
.arr-l,
.arr-r {
display: none;
color: #fff;
cursor: pointer;
position: absolute;
height: 40px;
width: 30px;
background-color: rgba(0, 0, 0, .3);
line-height: 40px;
text-align: center;
}
.arr-l {
top: 50%;
left: 0;
transform: translateY(-50%);
}
.arr-r {
right: 0;
top: 50%;
transform: translateY(-50%);
}
.current {
background-color: #fff;
}
動畫實現js文件animate.js:
function animate(obj, target, callback) {
clearInterval(obj.timer);
obj.timer = setInterval(function () {
if (target - obj.offsetLeft > 0) {
var step = Math.ceil((target - obj.offsetLeft) / 10);
} else {
var step = Math.floor((target - obj.offsetLeft) / 10);
}
if (obj.offsetLeft == target) {
clearInterval(obj.timer);
callback && callback();
}
obj.style.left = obj.offsetLeft + step + 'px';
}, 15)
}
index.js:
window.addEventListener('load', function () {
var arrl = this.document.querySelector('.arr-l');
var arrr = this.document.querySelector('.arr-r');
var box = this.document.querySelector('.box');
var boxWidth = box.offsetWidth;
box.addEventListener('mouseenter', function () {
arrl.style.display = 'block';
arrr.style.display = 'block';
clearInterval(timer);
timer = null;
})
box.addEventListener('mouseleave', function () {
arrl.style.display = 'none';
arrr.style.display = 'none';
timer = setInterval(function () {
arrr.click();
}, 2000);
});
var ul = box.querySelector('ul');
var ol = box.querySelector('ol');
for (var i = 0; i < ul.children.length; i++) {
var li = document.createElement('li');
li.setAttribute('data-index', i);
ol.appendChild(li);
ol.children[0].className = 'current';
li.addEventListener('click', function () {
for (var i = 0; i < ol.children.length; i++) {
ol.children[i].className = '';
}
this.className = 'current';
var dateindex = this.getAttribute('data-index');
num = dateindex;
circle = dateindex;
animate(ul, -dateindex * boxWidth);
});
}
var first = ul.children[0].cloneNode(true);
ul.appendChild(first);
var num = 0;
var circle = 0;
var flag = true;
arrr.addEventListener('click', function () {
if (flag) {
flag = false;
if (num == ul.children.length - 1) {
ul.style.left = 0;
num = 0;
}
num++;
animate(ul, -num * boxWidth, function () {
flag = true;
});
circle++;
if (circle == ol.children.length) {
circle = 0;
}
circleChange();
}
});
arrl.addEventListener('click', function () {
if (flag) {
flag = false;
if (num == 0) {
num = ul.children.length - 1;
ul.style.left = -num * boxWidth + 'px';
}
num--;
animate(ul, -num * boxWidth, function () {
flag = true;
});
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 = '';
}
ol.children[circle].className = 'current';
}
var timer = setInterval(function () {
arrr.click();
}, 2000);
})
注意事項
引用兩個js文件時,animate.js要在index.js之前引用,因爲index.js中要用到animate.js裏的函數。