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實(shí)現(xiàn)圖片首尾平滑輪播(JS原生方法—節(jié)流)

更新時間：2017年10月17日 09:00:16 作者：tainlx

下面小編就為大家?guī)硪黄獙?shí)現(xiàn)圖片首尾平滑輪播(JS原生方法—節(jié)流)。小編覺得挺不錯的，現(xiàn)在就分享給大家，也給大家做個參考。一起跟隨小編過來看看吧

首先給出HTML代碼，要注意輪播圖片表(#list)末尾加上第一個圖片1.jpg，在首部加上最后一個圖片5.jpg。

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>首尾輪播</title>
 <link rel="stylesheet" href="首尾輪播.css" rel="external nofollow" >
<script src="首尾輪播.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">&lt;</div>
  <div class="arrow" id="next">&gt;</div>


 </div>  

</body> 

</html>

接下來給出css和js代碼，大家可以酌情根據(jù)圖片的大小、數(shù)量、寬度，調(diào)整container、list的參數(shù)，這也是封裝JS所要考慮的參數(shù)。

*{
 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，我們可以通過改變speed變量來控制圖片切換的速度....這里用的是 element.style.transition來控制的過渡效果.

window.onload=function(){
 var container = document.getElementById('container');
 var list = document.getElementById('list');//獲取圖片容器
 var prev = document.getElementById('prev');//向前按鈕
 var next = document.getElementById('next');//向后按鈕
 var nowP = 1; //顯示位置
 var judge = null; //執(zhí)行權(quán)
 var speed = 0.1; // 切換速度 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);} //當(dāng)?shù)竭_(dá)圖片表左邊緣時與動畫同步切換 
     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);} //當(dāng)?shù)竭_(dá)圖片表右邊緣時與動畫同步切換 
    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);
 };

 
};

下面是一個演示demo，簡單來說原理就是在切換到圖片表首和表尾的動畫開始時，設(shè)置一個延遲執(zhí)行時間與動畫過渡時間相同的setTimeout函數(shù)來執(zhí)行瞬間切換，再通過節(jié)流來保證最大的切換速度(speed)。

本人也是初學(xué)前端，如果有幫助的話，點(diǎn)一下推薦吧