剪切背景以暴露下面的图层 [英] Cut the background to expose the layer below
本文介绍了剪切背景以暴露下面的图层的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
是否有一种方法可以剪切div背景以暴露下面的图层?例如:
Is there a way to cut a div background to expose the layer below?, like going from this:
对此:
欢迎使用任何前沿的CSS规则！
Any bleeding edge css rule is welcome!
更新
好，我编写了一个示例代码: http://jsfiddle.net/coma/9ae7g/1/
Ok, I've made a sample code: http://jsfiddle.net/coma/9ae7g/1/
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Menu</title>
<style type="text/css">
@charset 'UTF-8';
body {
padding: 0;
margin: 0;
font-family: "Lucida Grande", "Lucida Sans Unicode", Tahoma, Verdana, Arial, sans-serif;
font-size: 12px;
background: #fff url("http://colourlovers.com.s3.amazonaws.com/images/patterns/1762/1762793.png?1314797062");
}
a {
text-decoration: none;
}
#menu {
position: fixed;
top: 0;
left: 0;
bottom: 0;
width: 250px;
}
body.wide>#menu {
width: 0;
}
#menu * {
line-height: 1em;
}
#menu:after {
content: '';
position: absolute;
top: 0;
right: 0;
width: 5px;
height: 100%;
border-right: 1px solid #666;
pointer-events: none;
background: -moz-linear-gradient(left, rgba(0,0,0,0) 0%, rgba(0,0,0,0.25) 100%);
background: -webkit-linear-gradient(left, rgba(0,0,0,0) 0%,rgba(0,0,0,0.25) 100%);
background: -o-linear-gradient(left, rgba(0,0,0,0) 0%,rgba(0,0,0,0.25) 100%);
background: -ms-linear-gradient(left, rgba(0,0,0,0) 0%,rgba(0,0,0,0.25) 100%);
background: linear-gradient(to right, rgba(0,0,0,0) 0%,rgba(0,0,0,0.25) 100%);
}
#menu ul, #menu li {
padding: 0;
margin: 0;
list-style: none;
background-color: #fafafb;
}
#menu li {
position: relative;
}
#menu>a {
position: absolute;
left: 100%;
top: 50%;
z-index: 1;
display: block;
width: 10px;
height: 20px;
margin: -10px 0 0 0;
text-indent: -100em;
overflow: hidden;
border-radius: 0 2px 2px 0;
background-color: #666;
transition: background-color .3s ease-out;
-moz-transition: background-color .3s ease-out;
-webkit-transition: background-color .3s ease-out;
-o-transition: background-color .3s ease-out;
-ms-transition: background-color .3s ease-out;
}
#menu>a:before {
position: absolute;
top: 5px;
right: 4px;
display: block;
content: '';
border-width: 5px 6px 5px 0;
border-style: solid;
border-color: transparent #fff transparent transparent;
}
body.wide>#menu>a:before {
right: 2px;
border-width: 5px 0 5px 6px;
border-color: transparent transparent transparent #fff;
}
#menu>ul {
height: 100%;
background-color: #888;
overflow: hidden;
}
#menu>ul span, #menu>ul a {
display: block;
padding: .4em;
color: #666;
font-weight: bold;
border-bottom: 1px solid #999;
}
#menu>ul a {
border-top: 1px solid #fff;
border-bottom: 1px solid #e9ecee;
}
#menu>ul>li>span {
font-size: 1.25em;
font-weight: bold;
color: #666;
text-shadow: 0 1px 1px #fff;
background-color: #eee;
background-image: -moz-linear-gradient(top, rgba(0,0,0,0) 0%, rgba(0,0,0,0.2) 100%);
background-image: -webkit-linear-gradient(top, rgba(0,0,0,0) 0%, rgba(0,0,0,0.2) 100%);
background-image: -o-linear-gradient(top, rgba(0,0,0,0) 0%, rgba(0,0,0,0.2) 100%);
background-image: -ms-linear-gradient(top, rgba(0,0,0,0) 0%, rgba(0,0,0,0.2) 100%);
background-image: linear-gradient(top, rgba(0,0,0,0) 0%, rgba(0,0,0,0.2) 100%);
cursor: pointer;
transition: background-color .4s;
-moz-transition: background-color .4s;
-webkit-transition: background-color .4s;
-o-transition: background-color .4s;
-ms-transition: background-color .4s;
}
#menu>ul>li>span:hover {
background-color: #fff;
}
#menu>ul>li>ul {
display: none;
}
#menu>ul>li.opened>ul, #menu>ul>li.current_ancestor>ul {
display: block;
}
#menu>ul>li>ul>li>a {
font-size: 1.2em;
color: #4183c4;
transition: background-color .4s;
-moz-transition: background-color .4s;
-webkit-transition: background-color .4s;
-o-transition: background-color .4s;
-ms-transition: background-color .4s;
}
#menu>ul>li>ul>li.current>a, #menu>ul>li>ul>li.current>a:hover {
color: #fff;
background-color: #39f;
border-color: #39f;
}
#menu>ul>li>ul>li.current:after {
content: '';
position: absolute;
right: -1px;
top: 50%;
margin: -9px 0 0 0;
display: block;
border-width: 10px 10px 10px 0;
border-style: solid;
border-color: transparent #fff transparent transparent;
z-index: 1;
}
#menu>ul>li>ul>li>a:hover {
background: #fff;
}
#menu>ul>li>ul>li:last-child {
border-bottom: 1px solid #aaa;
}
#menu>ul>li>ul>li[data-count]:after {
position: absolute;
top: 50%;
right: 14px;
display: block;
content: attr(data-count);
padding: .26em .5em;
background-color: #fff;
border-radius: 8px;
font-size: 12px;
margin: -9px 0 0 0;
color: #777;
border-top: 1px solid #ccc;
}
#section {
height: 2000px;
}
</style>
</head>
<body>
<div id="menu">
<a title="cerrar o abrir el menú" href="#">toggle</a>
<ul>
<li class="first opened">
<span>Usuario</span>
<ul class="menu_level_1">
<li class="first">
<a href="/logout">Logout</a>
</li>
<li class="current">
<a href="/">Home</a>
</li>
<li>
<a href="/user/">Usuarios</a>
</li>
<li class="last">
<a href="/discount/">Descuentos</a>
</li>
</ul>
</li>
<li>
<span>Artistas</span>
<ul class="menu_level_1">
<li class="first">
<a href="/artist/">Artistas</a>
</li>
<li class="last">
<a href="/artists/top10">Top 10 (3)</a>
</li>
</ul>
</li>
<li>
<span>Obras</span>
<ul class="menu_level_1">
<li class="first">
<a href="/artwork/">Obras</a>
</li>
<li>
<a href="/artworks/destacadas">Destacadas (4)</a>
</li>
<li class="last">
<a href="/artworks/ofertas">Ofertas (3)</a>
</li>
</ul>
</li>
<li>
<span>Pedidos</span>
<ul class="menu_level_1">
<li class="first last">
<a href="/order/">Pedidos</a>
</li>
</ul>
</li>
<li>
<span>Blog</span>
<ul class="menu_level_1">
<li class="first">
<a href="/article/">Artículos</a>
</li>
<li class="last">
<a href="/category/">Categorías</a>
</li>
</ul>
</li>
<li class="last">
<span>Newsletter</span>
<ul class="menu_level_1">
<li class="first last">
<a href="/newsletter/">Emails</a>
</li>
</ul>
</li>
</ul>
</div>
<div id="section"></div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript">
$(function() {
var style = {
opened: 'opened',
wide: 'wide',
currentAncestor: 'current_ancestor'
};
var menu = $('#menu');
var items = $('#menu>ul>li');
var body = $('body');
items.filter('.' + style.currentAncestor)
.removeClass(style.currentAncestor)
.first()
.addClass(style.opened);
items.children('span').click(function(event) {
event.preventDefault();
var group = $(this).parent();
if(!group.hasClass(style.opened)) {
items.filter('.' + style.opened).removeClass(style.opened);
group.addClass(style.opened);
}
});
menu.children('a').click(function(event) {
event.preventDefault();
body.toggleClass(style.wide);
});
});
</script>
</body>
</html>
小鸟背景和高度为2000px的#部分仅用于通过移动内容进行测试.
The birdy background and the #section with a height of 2000px is just for testing by moving the content.
谢谢大家！
推荐答案
如果元素及其所有子元素都是透明的，则该元素将是透明的(没有 background-color ，没有 background-图片).
An element will be transparent if it and all of it's children are transparent (no background-color, no background-image).
要满足您的要求，这就是我要做的事情:
To accomplish what you're asking for, here's what I'd do:
- 避免在该组元素的容器上使用背景样式.
- 即使您必须对其进行裁剪以使其具有灵活性，也可以通过单个图像对这些单独的导航元素进行所有背景样式设置.
- 对于活动的导航元素，将背景图像交换为具有所需透明缩进的图像.
请参阅此JSFiddle(从您的代码中派生): http://jsfiddle.net/2XSd5/.这演示了我描述的方法:使所有背景透明，并使用背景图像进行剪切.这是我修改的代码:
See this JSFiddle, forked from your code: http://jsfiddle.net/2XSd5/. This demonstrates the approach I described: make all backgrounds transparent, and use a background image for the cut out. Here's the code that I modified:
#menu:after { background: none; }
#menu > ul > li > ul > li.current:after { content: none; }
#menu ul, #menu li { background-color: transparent; }
#menu > ul { background-color: transparent; }
#menu > ul > li > ul > li > a, #menu > ul > li > ul > li > a {
background-color: white;
}
#menu > ul > li > ul > li.current > a, #menu > ul > li > ul > li.current > a:hover {
background: url(data:image/png;base64,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) right center no-repeat;
color: grey;
}
这篇关于剪切背景以暴露下面的图层的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
