理解CSS Clip属性及用法

应用Clip属性实现的一个简单效果图：

 样式写法：

.my-element {
    position: absolute;
    clip: rect(10px  350px  170px  0); /* IE4 to IE7 */
    clip: rect(10px, 350px, 170px, 0); /* IE8+ & other browsers */
}

属性解析：

clip : { shape | auto | inherit } ;
auto 即浏览器默认解析，无clip效果，inderit 继承父层clip样式
shape 设置clip 形状，目前只支持 rect 即：矩形。 参数样例为：

clip: rect(<top>, <right>, <bottom>, <left>);

 有点不足的是 clip 属性只能使用于 位置属性设置为 absolute 或 fixed的元素

使用Clip实现的范例：

1

<style>
img {
  position: absolute;
  left: 10px;
  top: 60px;
  display: block;
  clip: rect(200px, 0, 0, 400px);
  -webkit-transition: all 0.5s ease-out;
  -moz-transition: all 0.5s ease-out;
  transition: all 0.5s ease-out;
}

span:hover ~ img {
  clip: rect(0, 400px, 200px, 0);
}

span {
  display: inline-block;
  padding: 10px;
  margin: 10px;
  background: #08C;
  color: white;
  font-family: "Helvetica", "Arial", sans-serif;
  font-weight: bold;
  text-shadow: 0 -1px rgba(0,0,0,0.3);
  text-align: center;
  cursor: pointer;
}

span:hover {
  background: #09C;
}
</style>
<span>Hover me</span>
<img src="http://lorempixel.com/400/200/">

 2

<style>
body {
  overflow: hidden;
}

ul {
  padding: 0;
  margin: 10px;
  list-style: none;
  width: 300px;
  height: 300px;
  box-shadow: 0 0 10px rgba(0,0,0,0.5);
}

ul:after {
  clear: both;
  content: "";
  display: table;
}

li {
  position: relative;
  float: left;
  width: 100px;
  height: 100px;
  background: url(' http://subtlepatterns.subtlepatterns.netdna-cdn.com/patterns/pw_maze_white.png');
  cursor: pointer;
}

li:nth-of-type(3n+1) {
  clear: both;
}

img {
  position: absolute;
  display: block;
  clip: rect(0, 100px, 100px, 0);
  -webkit-transition: all 0.2s ease-out, z-index 0s;
  -moz-transition: all 0.2s ease-out, z-index 0s;
  transition: all 0.2s ease-out, z-index 0s;
  opacity: 0.9;
}

li:hover img {
  clip: rect(0, 300px, 300px, 0);
  z-index: 2;
  opacity: 1;
}

li:nth-of-type(3n+1):hover img {
  left: 310px;
}

li:nth-of-type(3n+2):hover img {
  left: 210px;
}

li:nth-of-type(3n):hover img {
  left: 110px;
}

li:nth-of-type(n+4):nth-of-type(-n+6):hover img {
  top: -100px;
}

li:nth-of-type(n+7):nth-of-type(-n+9):hover img {
  top: -200px;
}
</style>
<ul>
  <li><img src="http://lorempixel.com/300/300/sports/"></li>
  <li><img src="http://lorempixel.com/300/300/animals/"></li>
  <li><img src="http://lorempixel.com/300/300/abstract/"></li>
  <li><img src="http://lorempixel.com/300/300/nightlife/"></li>
  <li><img src="http://lorempixel.com/300/300/city/"></li>
  <li><img src="http://lorempixel.com/300/300/food/"></li>
  <li><img src="http://lorempixel.com/300/300/people/"></li>
  <li><img src="http://lorempixel.com/300/300/nature/"></li>
  <li><img src="http://lorempixel.com/300/300/fashion/"></li>
</ul>

关于Clip属性应用的进阶使用范例: http://tympanus.net/codrops/2013/01/17/putting-css-clip-to-work-expanding-overlay-effect/

参考网址: http://tympanus.net/codrops/2013/01/16/understanding-the-css-clip-property/