@EncyKe
2016-05-09T02:19:00.000000Z
字数 7099
阅读 4982
JavaScript
前端
span
自定义index属性,以供JS选取实现单击小圆点切换图片功能;
<div id="container">
<div id="list" style="left: -600px;">
<img src="img/5.jpg" alt="1"/>
<img src="img/1.jpg" alt="1"/>
<img src="img/2.jpg" alt="2"/>
<img src="img/3.jpg" alt="3"/>
<img src="img/4.jpg" alt="4"/>
<img src="img/5.jpg" alt="5"/>
<img src="img/1.jpg" alt="5"/>
</div>
<div id="buttons">
<span index="1" class="on"></span>
<span index="2"></span>
<span index="3"></span>
<span index="4"></span>
<span index="5"></span>
</div>
<a href="javascript:;" id="prev" class="arrow"><</a>
<a href="javascript:;" id="next" class="arrow">></a>
</div>
/* reset */
*{
margin: 0;
padding: 0;
text-decoration: none;
}
body {
padding: 20px;
}
/* 外部大容器 */
#container {
width: 600px;
height: 400px;
border: 3px solid #333;
overflow: hidden;
position: relative;
margin: 0 auto;
}
/* 列表容器 */
#list {
width: 4200px;
/* 7张宽600px的图 */
height: 400px;
position: absolute;
z-index: 1;
}
#list img {
float: left;
}
/* 圆点小按钮容器 */
#buttons {
position: absolute;
height: 10px;
width: 100px;
z-index: 2;
bottom: 20px;
left: 250px;
}
/* 圆点小按钮 */
#buttons span {
cursor: pointer;
float: left;
border: 1px solid #fff;
width: 10px;
height: 10px;
border-radius: 50%;
background: #333;
margin-right: 5px;
}
/* 圆点小按钮激活状态 */
#buttons .on {
background: orangered;
}
/* 箭头 */
.arrow {
cursor: pointer;
display: none;
line-height: 39px;
text-align: center;
font-size: 36px;
font-weight: bold;
width: 40px;
height: 40px;
position: absolute;
z-index: 2;
top: 180px;
background-color: RGBA(0,0,0,.3);
color: #fff;
}
.arrow:hover {
background-color: RGBA(0,0,0,.7);
}
#container:hover .arrow {
display: block;
}
#prev {
left: 20px;
}
#next {
right: 20px;
}
window.onload = function () {
var container = document.getElementById('container');
var list = document.getElementById('list');
var buttons = document.getElementById('buttons').getElementsByTagName('span');
var prev = document.getElementById('prev');
var next = document.getElementById('next');
var index = 1;
var len = 5;
var animated = false;
var interval = 3000;
var timer;
// 封装点击箭头时两向滑动的函数;
function animate (offset) {
if (offset == 0) {
return;
}
animated = true;
// 位移持续时间;
var time = 300;
// 位移间隔时间;
var inteval = 50;
// 每次位移量;
var speed = offset/(time/inteval);
var left = parseInt(list.style.left) + offset;
var go = function (){
// 判断是否需要作位移;
if ( (speed > 0 && parseInt(list.style.left) < left) || (speed < 0 && parseInt(list.style.left) > left)) {
list.style.left = parseInt(list.style.left) + speed + 'px';
// 递归自身以实现位移动画;
setTimeout(go, inteval);
}
else {
list.style.left = left + 'px';
// 判断是否在1或5,超出时归位重置;
if(left>-200){
list.style.left = -600 * len + 'px';
}
if(left<(-600 * len)) {
list.style.left = '-600px';
}
animated = false;
}
}
go();
}
// 小圆点切换功能函数;
function showButton() {
// 重置所有按钮;
for (var i = 0; i < buttons.length ; i++) {
if( buttons[i].className == 'on'){
buttons[i].className = '';
break;
}
}
buttons[index - 1].className = 'on';
}
// 自动播放函数;
function play() {
timer = setTimeout(function () {
prev.onclick();
play();
}, interval);
}
// 停止自动播放函数;
function stop() {
clearTimeout(timer);
}
// 右箭头点击切换事件;
next.onclick = function () {
if (animated) {
return;
}
// 同步小圆点的index;
if (index == 1) {
index = 5;
}
else {
index -= 1;
}
animate(600);
showButton();
}
// 左箭头点击切换事件;
prev.onclick = function () {
if (animated) {
return;
}
// 同步小圆点的index;
if (index == 5) {
index = 1;
}
else {
index += 1;
}
animate(-600);
showButton();
}
// 单击小圆点切换事件;
for (var i = 0; i < buttons.length; i++) {
buttons[i].onclick = function () {
// 停留当前图片时重复点击不刷新;
if (animated) {
return;
}
if(this.className == 'on') {
return;
}
var myIndex = parseInt(this.getAttribute('index'));
var offset = -600 * (myIndex - index);
animate(offset);
// 更新index值;
index = myIndex;
showButton();
}
}
container.onmouseover = stop;
container.onmouseout = play;
play();
}
Demo的思想是头尾衔接一张图片以达到无限轮播的效果,但如此一来HTML冗余度比较高,不妨用DOM节点方式优化:
window.onload = function () {
var container = document.getElementById('container');
var list = document.getElementById('list');
var imgs = list.getElementsByTagName('img');
var buttons = document.getElementById('buttons').getElementsByTagName('span');
var prev = document.getElementById('prev');
var next = document.getElementById('next');
var index = 1;
var len = imgs.length;
var animated = false;
var interval = 3000;
var timer;
var lastImg = document.createElement('img');
var firstImg = document.createElement('img');
firstImg.src = imgs[len-1].src;
list.insertBefore(firstImg, imgs[0]);
lastImg.src = imgs[0].src;
list.appendChild(lastImg);
// 封装点击箭头时两向滑动的函数;
function animate (offset) {
if (offset == 0) {
return;
}
animated = true;
// 位移持续时间;
var time = 300;
// 位移间隔时间;
var inteval = 50;
// 每次位移量;
var speed = offset/(time/inteval);
var left = parseInt(list.style.left) + offset;
var go = function (){
// 判断是否需要作位移;
if ( (speed > 0 && parseInt(list.style.left) < left) || (speed < 0 && parseInt(list.style.left) > left)) {
list.style.left = parseInt(list.style.left) + speed + 'px';
// 递归自身以实现位移动画;
setTimeout(go, inteval);
}
else {
list.style.left = left + 'px';
// 判断是否在1或5,超出时归位重置;
if(left>-200){
list.style.left = -600 * len + 'px';
}
if(left<(-600 * len)) {
list.style.left = '-600px';
}
animated = false;
}
}
go();
}
// 小圆点切换功能函数;
function showButton() {
// 重置所有按钮;
for (var i = 0; i < buttons.length ; i++) {
if( buttons[i].className == 'on'){
buttons[i].className = '';
break;
}
}
buttons[index - 1].className = 'on';
}
// 自动播放函数;
function play() {
timer = setTimeout(function () {
prev.onclick();
play();
}, interval);
}
// 停止自动播放函数;
function stop() {
clearTimeout(timer);
}
// 右箭头点击切换事件;
next.onclick = function () {
if (animated) {
return;
}
// 同步小圆点的index;
if (index == 1) {
index = 5;
}
else {
index -= 1;
}
animate(600);
showButton();
}
// 左箭头点击切换事件;
prev.onclick = function () {
if (animated) {
return;
}
// 同步小圆点的index;
if (index == 5) {
index = 1;
}
else {
index += 1;
}
animate(-600);
showButton();
}
// 单击小圆点切换事件;
for (var i = 0; i < buttons.length; i++) {
buttons[i].onclick = function () {
// 停留当前图片时重复点击不刷新;
if (animated) {
return;
}
if(this.className == 'on') {
return;
}
var myIndex = parseInt(this.getAttribute('index'));
var offset = -600 * (myIndex - index);
animate(offset);
// 更新index值;
index = myIndex;
showButton();
}
}
container.onmouseover = stop;
container.onmouseout = play;
play();
}
这样,HTML只需放置5张图片即可——
<div id="list" style="left: -600px;">
<img src="img/1.jpg" alt="1"/>
<img src="img/2.jpg" alt="2"/>
<img src="img/3.jpg" alt="3"/>
<img src="img/4.jpg" alt="4"/>
<img src="img/5.jpg" alt="5"/>
</div>
与JS原生方法同。
$(function () {
var container = $('#container');
var list = $('#list');
var buttons = $('#buttons span');
var prev = $('#prev');
var next = $('#next');
var index = 1;
var len = 5;
var interval = 3000;
var timer;
function animate (offset) {
var left = parseInt(list.css('left')) + offset;
if (offset>0) {
offset = '+=' + offset;
}
else {
offset = '-=' + Math.abs(offset);
}
list.animate({'left': offset}, 300, function () {
if(left > -200){
list.css('left', -600 * len);
}
if(left < (-600 * len)) {
list.css('left', -600);
}
});
}
function showButton() {
buttons.eq(index-1).addClass('on').siblings().removeClass('on');
}
function play() {
timer = setTimeout(function () {
next.trigger('click');
play();
}, interval);
}
function stop() {
clearTimeout(timer);
}
next.bind('click', function () {
if (list.is(':animated')) {
return;
}
if (index == 5) {
index = 1;
}
else {
index += 1;
}
animate(-600);
showButton();
});
prev.bind('click', function () {
if (list.is(':animated')) {
return;
}
if (index == 1) {
index = 5;
}
else {
index -= 1;
}
animate(600);
showButton();
});
buttons.each(function () {
$(this).bind('click', function () {
if (list.is(':animated') || $(this).attr('class')=='on') {
return;
}
var myIndex = parseInt($(this).attr('index'));
var offset = -600 * (myIndex - index);
animate(offset);
index = myIndex;
showButton();
})
});
container.hover(stop, play);
play();
});