CSS3随机背景图片切换特效

定义和用法
通过 @keyframes 规则，您能够创建动画。
创建动画的原理是，将一套 CSS 样式逐渐变化为另一套样式。
在动画过程中，您能够多次改变这套 CSS 样式。
以百分比来规定改变发生的时间，或者通过关键词 "from" 和 "to"，等价于 0% 和 100%。
0% 是动画的开始时间，100% 动画的结束时间。
为了获得最佳的浏览器支持，您应该始终定义 0% 和 100% 选择器。
注释：请使用动画属性来控制动画的外观，同时将动画与选择器绑定。

核心css部分(记得切换图片地址)

body {
	background: #000;
	background-attachment: fixed;
	word-wrap: break-word;
	-webkit-background-size: cover;
	-moz-background-size: cover;
	background-size: cover;
	background-repeat: no-repeat
}
 
ul {
	list-style: none
}
 
.cb-slideshow li:nth-child(1) span {
	background-image: url(https://random.52ecy.cn/randbg.php?v=1520341099)
}
 
.cb-slideshow li:nth-child(2) span {
	background-image: url(https://random.52ecy.cn/randbg.php?v=1520341159)
}
 
.cb-slideshow li:nth-child(3) span {
	background-image: url(https://random.52ecy.cn/randbg.php?v=1520341149)
}
 
.cb-slideshow li:nth-child(4) span {
	background-image: url(https://random.52ecy.cn/randbg.php?v=1520341139)
}
 
.cb-slideshow li:nth-child(5) span {
	background-image: url(https://random.52ecy.cn/randbg.php?v=1520341129)
}
 
.cb-slideshow li:nth-child(6) span {
	background-image: url(https://random.52ecy.cn/randbg.php?v=1520341119)
}
 
.cb-slideshow,.cb-slideshow:after {
	position: fixed;
	width: 100%;
	height: 100%;
	top: 0;
	left: 0;
	z-index: -2
}
 
.cb-slideshow:after {
	content: ''
}
 
.cb-slideshow li span {
	width: 100%;
	height: 100%;
	position: absolute;
	top: 0;
	left: 0;
	color: transparent;
	background-size: cover;
	background-position: 50% 50%;
	background-repeat: none;
	opacity: 0;
	z-index: -2;
	-webkit-backface-visibility: hidden;
	-webkit-animation: imageAnimation 36s linear infinite 0s;
	-moz-animation: imageAnimation 36s linear infinite 0s;
	-o-animation: imageAnimation 36s linear infinite 0s;
	-ms-animation: imageAnimation 36s linear infinite 0s;
	animation: imageAnimation 36s linear infinite 0s
}
 
.cb-slideshow li:nth-child(2) span {
	-webkit-animation-delay: 6s;
	-moz-animation-delay: 6s;
	-o-animation-delay: 6s;
	-ms-animation-delay: 6s;
	animation-delay: 6s
}
 
.cb-slideshow li:nth-child(3) span {
	-webkit-animation-delay: 12s;
	-moz-animation-delay: 12s;
	-o-animation-delay: 12s;
	-ms-animation-delay: 12s;
	animation-delay: 12s
}
 
.cb-slideshow li:nth-child(4) span {
	-webkit-animation-delay: 18s;
	-moz-animation-delay: 18s;
	-o-animation-delay: 18s;
	-ms-animation-delay: 18s;
	animation-delay: 18s
}
 
.cb-slideshow li:nth-child(5) span {
	-webkit-animation-delay: 24s;
	-moz-animation-delay: 24s;
	-o-animation-delay: 24s;
	-ms-animation-delay: 24s;
	animation-delay: 24s
}
 
.cb-slideshow li:nth-child(6) span {
	-webkit-animation-delay: 30s;
	-moz-animation-delay: 30s;
	-o-animation-delay: 30s;
	-ms-animation-delay: 30s;
	animation-delay: 30s
}
 
@-webkit-keyframes imageAnimation {
	0% {
		opacity: 0;
		-webkit-animation-timing-function: ease-in
	}
 
	8% {
		opacity: 1;
		-webkit-transform: scale(1.05);
		-webkit-animation-timing-function: ease-out
	}
 
	17% {
		opacity: 1;
		-webkit-transform: scale(1.1) rotate(0)
	}
 
	25% {
		opacity: 0;
		-webkit-transform: scale(1.1) rotate(0)
	}
 
	100% {
		opacity: 0
	}
}

当然还是需要配合HTML代码的
HTML部分(其中的文字部分和<li>的数量是可以随意更改的)

<ul class="cb-slideshow">
	<li>
		<span>杨</span></li>
	<li>
		<span>小</span></li>
	<li>
		<span>杰</span></li>
	<li>
		<span>转</span></li>
	<li>
		<span>载</span></li>
	<li>
		<span>的</span></li>
</ul>

注意：<li>的数量要和css对应上，并且至少要两个以上。另外ie浏览器是不支持CSS3的特效