实现图片首尾平滑轮播(JS原生方法—节流)

Francesca ·

更新时间:2024-11-15

· 926 次阅读

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" rel="external nofollow" >
<script src="首尾轮播.js"></script>
</head>
<body>
 <div id="container">
  <div id="list">
   <div><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="../imgs/5.jpg" alt=""></a></div>
   <div><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="../imgs/1.jpg" alt=""></a></div>
   <div><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="../imgs/2.jpg" alt=""></a></div>
   <div><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="../imgs/3.jpg" alt=""></a></div>
   <div><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="../imgs/4.jpg" alt=""></a></div>
   <div><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="../imgs/5.jpg" alt=""></a></div>
   <div><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><img src="../imgs/1.jpg" alt=""></a></div>
  </div>
  <div class="arrow" id="prev"><</div>
  <div class="arrow" id="next">></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: 0;
 padding: 0;
}
#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: 2;
 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)。

本人也是初学前端，如果有帮助的话，点一下推荐吧