javascript - 可滚动的图片库循环在最后一张图片之后工作,它应该再次从第一张图片开始
问题描述
我正在尝试使用javascript创建一个可滚动的图片库,所以我可以创建它,但现在我希望它像无限循环一样工作,即一旦它到达最后一张图片,然后在下一次点击时它应该再次从第一张图片开始
这是我的html代码
var width = 130; // image width
var count = 4; // visible images count
var list = carousel.querySelector('ul');
var listElems = carousel.querySelectorAll('li');
var position = 0;
// shift left
document.querySelector('.prev').onclick = function() {
position += width * count;
position = Math.min(position, 0);
list.style.marginLeft = position + 'px';
};
// shift right
document.querySelector('.next').onclick = function() {
position -= width * count;
position = Math.max(position, -width * (listElems.length - count));
list.style.marginLeft = position + 'px';
};
.carousel {
position: relative;
width: 508px;
padding: 10px 40px;
border: 1px solid #CCC;
border-radius: 15px;
background: #eee;
}
.carousel img {
width: 130px;
height: 130px;
}
.arrow {
position: absolute;
top: 40%;
padding: 0;
background: #ddd;
border-radius: 15px;
border: 1px solid gray;
font-size: 24px;
line-height: 24px;
color: #444;
}
.arrow:focus {
outline: none;
}
.arrow:hover {
background: #ccc;
cursor: pointer;
}
.prev {
left: 7px;
}
.next {
right: 7px;
}
.gallery {
width: 530px;
overflow: hidden;
}
.gallery ul {
height: 130px;
width: 10000px;
margin: 0;
padding: 0;
list-style: none;
transition: margin-left 350ms;
font-size: 0;
}
.gallery li {
display: inline-block;
}
<div class="carousel" id="carousel">
<button class="arrow prev">⇦</button>
<div class="gallery">
<ul class="images">
<li><img src="https://en.js.cx/carousel/1.png"></li>
<li><img src="https://en.js.cx/carousel/2.png"></li>
<li><img src="https://en.js.cx/carousel/3.png"></li>
<li><img src="https://en.js.cx/carousel/4.png"></li>
<li><img src="https://en.js.cx/carousel/5.png"></li>
<li><img src="https://en.js.cx/carousel/6.png"></li>
<li><img src="https://en.js.cx/carousel/7.png"></li>
<li><img src="https://en.js.cx/carousel/8.png"></li>
<li><img src="https://en.js.cx/carousel/9.png"></li>
<li><img src="https://en.js.cx/carousel/10.png"></li>
<li><img src="https://en.js.cx/carousel/5.png"></li>
<li><img src="https://en.js.cx/carousel/1.png"></li>
<li><img src="https://en.js.cx/carousel/8.png"></li>
</ul>
</div>
<button class="arrow next">⇨</button>
</div>
它工作得很好,就像点击按钮图像是 srcolling 但我希望它可以在无限循环中滚动
解决方案
position
在将' 变量分配给 之前,您可以通过检查来做到这一点style.marginLeft
:
- 对于
next
按钮,变量通常position
等于然后分配给所以轮播重新开始。-((the number of the carousel elements - four (as 4 cards should be shown)) multiplied by the width of an element)
-((listElems.length - 4) * width)
0
position
- 对于
prev
按钮,position
变量等于0
然后分配给它-((the number of the carousel elements - four (as 4 cards should be shown)) multiplied by the width of an element)
。
这是一个演示:
var width = 130; // image width
var count = 4; // visible images count
var list = carousel.querySelector('ul');
var listElems = carousel.querySelectorAll('li');
var position = 0;
// shift left
document.querySelector('.prev').onclick = function() {
position += width * count;
position = Math.min(position, 0);
/** check if we have to loop back from the end **/
position === 0 && (position = -((listElems.length - 4) * width));
list.style.marginLeft = position + 'px';
};
// shift right
document.querySelector('.next').onclick = function() {
position -= width * count;
position = Math.max(position, -width * (listElems.length - count));
/** check if we have to loop back from the begining **/
position === -((listElems.length - 4) * width) && (position = 0);
list.style.marginLeft = position + 'px';
};
.carousel {
position: relative;
width: 508px;
padding: 10px 40px;
border: 1px solid #CCC;
border-radius: 15px;
background: #eee;
}
.carousel img {
width: 130px;
height: 130px;
}
.arrow {
position: absolute;
top: 40%;
padding: 0;
background: #ddd;
border-radius: 15px;
border: 1px solid gray;
font-size: 24px;
line-height: 24px;
color: #444;
}
.arrow:focus {
outline: none;
}
.arrow:hover {
background: #ccc;
cursor: pointer;
}
.prev {
left: 7px;
}
.next {
right: 7px;
}
.gallery {
width: 530px;
overflow: hidden;
}
.gallery ul {
height: 130px;
width: 10000px;
margin: 0;
padding: 0;
list-style: none;
transition: margin-left 350ms;
font-size: 0;
}
.gallery li {
display: inline-block;
}
<div class="carousel" id="carousel">
<button class="arrow prev">⇦</button>
<div class="gallery">
<ul class="images">
<li><img src="https://en.js.cx/carousel/1.png"></li>
<li><img src="https://en.js.cx/carousel/2.png"></li>
<li><img src="https://en.js.cx/carousel/3.png"></li>
<li><img src="https://en.js.cx/carousel/4.png"></li>
<li><img src="https://en.js.cx/carousel/5.png"></li>
<li><img src="https://en.js.cx/carousel/6.png"></li>
<li><img src="https://en.js.cx/carousel/7.png"></li>
<li><img src="https://en.js.cx/carousel/8.png"></li>
<li><img src="https://en.js.cx/carousel/9.png"></li>
<li><img src="https://en.js.cx/carousel/10.png"></li>
<li><img src="https://en.js.cx/carousel/5.png"></li>
<li><img src="https://en.js.cx/carousel/1.png"></li>
<li><img src="https://en.js.cx/carousel/8.png"></li>
</ul>
</div>
<button class="arrow next">⇨</button>
</div>
推荐阅读
- java - 尝试将外部 Jar 添加到 Java 项目(没有 Maven)
- python - 如何发送响应烧瓶 api 并运行 python 脚本的图像?
- bash - 使用 while 条件 ping 主机的 Bash 脚本
- swift - 在@State chage 之后,SwiftUI 在 for 循环中重新渲染代码
- javascript - 我可以使用 array.filter() 从数组中获取样本元素吗?
- c++ - 如何使用 C++ 元编程在编译时包装和重载所有成员函数(来自未知类)?
- java - Java中if语句中的for循环
- javascript - 如何防止用户使用 JavaScript 复制他的 IP?
- swiftui - SwiftUI - 在当前视图中为新图像设置动画
- java - 读取文本文件或向 ArrayList 添加元素是否更快?