當我們前後端交互的時候，我們寫的輪播圖要靈活一點。當我們寫滑動形式的輪播圖時，最後面往往要加上若干個代碼塊和前幾個相同，以此達到輪播圖最後一張到第一張的過渡。
以這個爲例
這是6個圖片，但是我們要最後再加上4個已完成過渡
以往像這種我會直接在html裏面寫10個
但是前後端交互的時候，a標籤的數量都時後端遍歷傳過來的。所以最後四個我們應該用js來解決。
這時候我們就會想到js中的appendChild或者jQuery中的append方法，但是如果我們直接這樣添加的話，只會把前四個轉移到最後四個的位置，只是調換了位置，並沒有實現了添加的效果。
$(".carousel_box>a").eq(3).appendTo($(".carousel_box"))
這時候我們應該用js先複製一下a代碼塊，再添加
js：
var a=document.getElementsByClassName("carousel_box")[0];
var c=a.getElementsByTagName("a")[3];
var e=c.cloneNode(true);
a.appendChild(e);
jQuery：
$(".carousel_box>a").eq(3).clone().appendTo($(".carousel_box"))
整個輪播圖的代碼如下，歡迎各位大佬提出意見、建議和錯誤
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>carousel</title>
<link rel="stylesheet" type="text/css" href="css/carousel.css"/>
</head>
<body>
<div class="carousel">
<div class="carousel_contain">
<div class="carousel_box">
<a href="javascript:;" target="_blank">
<img src="img/S1.jpg"/>
<div class="names">
<h3 class="name_">1</h3>
<h4 class="grade_"></h4>
</div>
</a>
<a href="javascript:;" target="_blank">
<img src="img/S1.jpg"/>
<div class="names">
<h3 class="name_">2</h3>
<h4 class="grade_"></h4>
</div>
</a>
<a href="javascript:;" target="_blank">
<img src="img/S1.jpg"/>
<div class="names">
<h3 class="name_">3</h3>
<h4 class="grade_"></h4>
</div>
</a>
<a href="javascript:;" target="_blank">
<img src="img/S1.jpg"/>
<div class="names">
<h3 class="name_">4</h3>
<h4 class="grade_"></h4>
</div>
</a>
<a href="javascript:;" target="_blank">
<img src="img/S1.jpg"/>
<div class="names">
<h3 class="name_">5</h3>
<h4 class="grade_"></h4>
</div>
</a>
<a href="javascript:;" target="_blank">
<img src="img/S1.jpg"/>
<div class="names">
<h3 class="name_">6</h3>
<h4 class="grade_"></h4>
</div>
</a>
</div>
</div>
<ul class="switchable_triggers">
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
</ul>
</div>
</body>
<script src="js/jquery-1.12.4.min.js"></script>
<script src="js/carousel.js"></script>
</html>
*{
box-sizing: border-box;
margin: 0;
padding: 0;
}
.carousel{
position: relative;
height: 374px;
}
.carousel_contain{
clear: both;
position: relative;
overflow: hidden;
margin: 0;
height: 333px;
width: 1200px;
margin: 0 auto;
}
.carousel_box{
position: absolute;
/*left: -1168px;*/
width: 17520px;
transition-property: none;
transition-duration: 500ms;
transition-timing-function: ease-in-out;
}
.carousel_box a{
float: left;
margin: 2px 8px;
height: 327px;
width: 284px;
display: inline;
text-align: center;
background: #f7f7f7;
box-shadow: 0 0 2px 2px #e0dfdf;
background-image: url(../img/home_poeple_bg.png);
}
.carousel_box a img{
height: 185px;
display: block;
margin: 14px auto 5px;
padding: 3px;
box-sizing: border-box;
transition: all 0.3s;
box-shadow: 0 0 3px 3px #ddd;
}
.switchable_triggers{
display: block;
height:20px;
text-align: center;
}
.switchable_triggers li{
display: inline-block;
width: 17px;
height: 6px;
margin: 10px 3px 0 0;
font-size: 0px;
background: url(../img/navigator.png) -80px -10px no-repeat;
outline: none;
overflow: hidden;
float: left;
}
.switchable_triggers li:nth-child(1){
background: url(../img/navigator.png) -80px 0px no-repeat;
}
$(function(){
var width_=$(".switchable_triggers>li").length*20+"px";
$(".switchable_triggers").css("width",width_);
$(".switchable_triggers").css("margin","0 auto")
var storage=$("carousel_box>a");
for (var i = 0; i <4; i++) {
$(".carousel_box>a").eq(i).clone().appendTo($(".carousel_box"))
}
var current_index = 0;
var total = $(".carousel_box>a").length-4;
function carousel_play(){
current_index++;
if(current_index == total){
$(".switchable_triggers>li").eq(0).css("background-position","-80px 0px");
$(".switchable_triggers>li").eq(0).siblings().css("background-position","-80px -10px");
}
if(current_index > total) {
$(".carousel_box").css({
marginLeft: 0
});
current_index = 1;
}
$(".carousel_box").stop().animate({
marginLeft: -300 * current_index + "px"
}, 500);
$(".switchable_triggers>li").eq(current_index).css("background-position","-80px 0px");
$(".switchable_triggers>li").eq(current_index).siblings().css("background-position","-80px -10px");
}
var timer=setInterval(carousel_play,2000)
$(".switchable_triggers>li").hover(function(){
switchable_triggers_index=$(this).index();
clearInterval(timer);
current_index=switchable_triggers_index-1;
carousel_play();
},function(){
timer=setInterval(carousel_play,2000);
})
$(".carousel").mousemove(function(){
clearInterval(timer);
});
$(".carousel").mouseleave(function(){
timer=setInterval(carousel_play,2000);
})
});