图片首尾平滑轮播(JS原生方法—节流)<原创>

时间:2023-03-10 01:30:42
图片首尾平滑轮播(JS原生方法—节流)<原创>

首先给出HTML代码,要注意轮播图片表(#list)末尾加上第一个图片1.jpg,在首部加上最后一个图片5.jpg。

 <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>首尾轮播</title>
<link rel="stylesheet" href="首尾轮播.css">
<script src="首尾轮播.js"></script>
</head>
<body>
<div id="container">
<div id="list" style="left: -500px">
<div><a href="#"><img src="../imgs/5.jpg" alt=""></a></div>
<div><a href="#"><img src="../imgs/1.jpg" alt=""></a></div>
<div><a href="#"><img src="../imgs/2.jpg" alt=""></a></div>
<div><a href="#"><img src="../imgs/3.jpg" alt=""></a></div>
<div><a href="#"><img src="../imgs/4.jpg" alt=""></a></div>
<div><a href="#"><img src="../imgs/5.jpg" alt=""></a></div>
<div><a href="#"><img src="../imgs/1.jpg" alt=""></a></div>
</div> <div class="arrow" id="prev">&lt;</div>
<div class="arrow" id="next">&gt;</div> </div> </body> </html>

接下来给出css和js代码,大家可以酌情根据图片的大小、数量、宽度,调整container、list的参数,这也是封装JS所要考虑的参数。

 *{
margin:;
padding:;
} #container{
height: 400px;
width: 500px;
margin: 0 auto;
position: relative;
overflow: hidden;
border: 1px solid black;
} #list>div {
float: left;
}
#list{
position: absolute;
height: 400px;
width: 3600px; } #list img{
height: 400px;
width: 500px;
}
.arrow {
user-select:none;
position: absolute;
top:150px;
z-index:;
background-color: #aaa;
height: 100px;
width: 80px;
cursor: pointer;
opacity: 0.5;
display: none;
line-height: 100px;
text-align: center;
color: #222;
font-size: 3em; }
#container:hover .arrow{
display: block;
}
#prev{
left:20px;
} #next{
right: 20px;
}

在JS中,我们可以通过改变speed变量来控制图片切换的速度....这里用的是 element.style.transition来控制的过渡效果.

 window.onload=function(){
var container = document.getElementById('container');
var list = document.getElementById('list');//获取图片容器
var prev = document.getElementById('prev');//向前按钮
var next = document.getElementById('next');//向后按钮
var nowP = 1; //显示位置
var judge = null; //执行权
var speed = 0.1; // 切换速度 秒
prev.onclick=function(){
if(!judge){
judge = setTimeout(function(){
if(nowP==1){setTimeout(function(){
list.style.transition="left 0s";
list.style.left = "-2500px"; 
nowP = 5;},speed*1000);} //当到达图片表左边缘时与动画同步切换
list.style.transition = "left "+speed+"s";
move(500);
nowP--;
judge = null;
},speed*1000);
}
};
next.onclick=function(){
if(!judge){
judge = setTimeout(function(){
if(nowP==5){setTimeout(function(){
list.style.transition="left 0s";
list.style.left = "-500px";
nowP = 1;},speed*1000);} //当到达图片表右边缘时与动画同步切换
list.style.transition = "left "+speed+"s";
move(-500);
nowP++;
judge = null;
},speed*1000);
} }; function move(num){
var term = parseInt(list.style.left) + num ;
list.style.left = term+"px";
} var roll= setInterval(function(){
next.onclick();
},2000); container.onmouseenter=function(){
clearInterval(roll);
}; container.onmouseleave=function()
{
roll=setInterval(function(){
next.onclick();
},2000);
}; };

下面是一个演示demo,简单来说原理就是在切换到图片表首和表尾的动画开始时,设置一个延迟执行时间与动画过渡时间相同的setTimeout函数来执行瞬间切换,再通过节流来保证最大的切换速度(speed)。

节流的原理我是参考的以下两位元老的文章:

阮一峰Javascript标准参考教程(事件类型scroll事件小结)
mqyqing.fengJavaScript专题之跟着 underscore 学节流.Github

本人也是初学前端,如果有帮助的话,点一下推荐吧

图片首尾平滑轮播(JS原生方法—节流)<原创>