CSS知识总结(九)
CSS常用样式
10.自定义动画
1)关键帧(keyframes)
被称为关键帧,其类似于Flash中的关键帧。
在CSS3中其主要以“@keyframes”开头,后面紧跟着是动画名称加上一对花括号“{…}”,括号中就是一些不同时间段样式规则。
语法:@keyframes animationname {keyframes-selector {css-styles;}}
animationname:定义动画的名称。
keyframes-selector: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%。建议定义百分比选择器。
css-styles:通过 @keyframes 规则,您能够创建动画,就是将一套 CSS 样式逐渐变化为另一套样式,并且能够多次改变这套 CSS 样式。
兼容性:目前浏览器都不支持@keyframes规则,需要加上前缀"-moz-","-o-","-webkit-"。
例子:
@-webkit-keyframes FromLeftToRight{ /* Safari 和 Chrome */ 0% {left:0;} 100% {left:800px;} } @-moz-keyframes FromLeftToRight{ /* Firefox */ 0% {left:0;} 100% {left:800px;} } @-o-keyframes FromLeftToRight{ /* Opera */ 0% {left:0;} 100% {left:800px;} } @keyframes FromLeftToRight{ 0% {left:0;} 100% {left:800px;} }
2)动画名称(animation-name)
元素所应用的动画名称,必须与规则@keyframes配合使用,因为动画名称由@keyframes定义。
animation-name :none | <identifier>
<identifier>:定义一个或多个动画名称,如果是多个,用逗号分隔。
例子:
div{ -webkit-animation-name:FromLeftToRight; -moz-animation-name:FromLeftToRight; -o-animation-name:FromLeftToRight; animation-name:FromLeftToRight; } @-webkit-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:800px;} } @-moz-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:800px;} } @-o-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:800px;} } @keyframes FromLeftToRight{ 0% {left:0;} 100% {left:800px;} }
3)动画时间(animation-duration)
指定对象动画的持续时间
animation-duration:<time>
例子 源代码:
/* CSS代码 */ .duration{ width:100px; height:100px; background:#000; position:relative; -webkit-animation-name:FromLeftToRight; -webkit-animation-duration:3s; -moz-animation-name:FromLeftToRight; -moz-animation-duration:3s; animation-name:FromLeftToRight; animation-duration:3s; } @-webkit-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} } @-moz-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} } @keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} }
<!-- HTML代码 --> <body> <p>请按F5刷新动画(矩形用3秒向右移动500px)</p> <div class="duration"></div> </body>
效果:
请按F5刷新动画(矩形用3秒向右移动500px)
4)动画的过渡速度(animation-timing-function)
animation-timing-function : ease | linear | ease-in | ease-out | ease-in-out | cubic-bezier(n,n,n,n)
①ease : 默认值,逐渐变慢(等于 cubic-bezier(0.25,0.1,0.25,1))
②linear : 匀速过渡效果(等于 cubic-bezier(0,0,1,1))
③ease-in : 加速的过渡效果(等于 cubic-bezier(0.42,0,1,1))
④ease-out : 减速的过渡效果(等于 cubic-bezier(0,0,0.58,1))
⑤ease-in-out : 加速然后减速(等于cubic-bezier (0.42, 0, 0.58, 1))
⑥cubic-bezier(n,n,n,n):在 cubic-bezier 函数中定义自己的值,可能的值是 0 至 1 之间的数值。
例子 源代码:
/* CSS代码 */ .function{ width:100px; height:100px; background:#ccc; position:relative; margin:5px; -webkit-animation-name:FromLeftToRight; -webkit-animation-duration:3s; -moz-animation-name:FromLeftToRight; -moz-animation-duration:3s; animation-name:FromLeftToRight; animation-duration:3s; } .ease-in{ -webkit-animation-timing-function:ease-in; -moz-animation-timing-function:ease-in; animation-timing-function:ease-in; } .ease-out{ -webkit-animation-timing-function:ease-out; -moz-animation-timing-function:ease-out; animation-timing-function:ease-out; } @-webkit-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} } @-moz-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} } @keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} }
<!-- HTML代码 --> <body> <p>请按F5刷新动画(两个矩形同样在3秒用不同的速率向右移动500px)</p> <div class="function ease-in">ease-in</div> <div class="function ease-out">ease-out</div> </body>
效果:
请按F5刷新动画(两个矩形同样在3秒用不同的速率向右移动500px)
5)动画延迟时间(animation-delay)
指定对象动画延迟的时间
例子 源代码:
/* CSS代码 */ .delay{ width:100px; height:100px; background:#000; position:relative; -webkit-animation-name:FromLeftToRight; -webkit-animation-duration:3s; -webkit-animation-delay:2s; -moz-animation-name:FromLeftToRight; -moz-animation-duration:3s; -moz-animation-delay:2s; animation-name:FromLeftToRight; animation-duration:3s; animation-delay:2s; } @-webkit-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} } @-moz-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} } @keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} }
<!-- HTML代码 --> <body> <p>请按F5刷新动画(刷新后请等待2秒启动动画)</p> <div class="delay"></div> </body>
效果:
请按F5刷新动画(刷新后请等待2秒启动动画)
6)动画执行次数(animation-iteration-count)
animation-iteration-count:infinite | <number>
infinite表示无限次数,number指定循环次数。
例子 源代码:
/* CSS代码 */ .infinite{ width:100px; height:100px; background:#000; position:relative; -webkit-animation-name:FromLeftToRight; -webkit-animation-duration:3s; -webkit-animation-iteration-count:infinite; -moz-animation-name:FromLeftToRight; -moz-animation-duration:3s; -moz-animation-iteration-count:infinite; animation-name:FromLeftToRight; animation-duration:3s; animation-iteration-count:infinite; } @-webkit-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} } @-moz-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} } @keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} }
<!-- HTML代码 --> <body> <p>动画全自动无限循环播放</p> <div class="infinite"></div> </body>
效果:
动画全自动无限循环播放
7)动画的顺序(animation-direction)
设置对象动画在循环中是否反向运动
animation-direction : normal | reverse | alternate | alternate-reverse
normal:正常方向
reverse:反方向运行
alternate:动画先正常运行再反方向运行,并持续交替运行
alternate-reverse:动画先反运行再正方向运行,并持续交替运行
例子 源代码:
/* CSS代码 */ .box{ width:100px; height:50px; background:#ccc; margin:5px; position:relative; -webkit-animation-name:FormLeftToRight; -moz-animation-name:FormLeftToRight; animation-name:FormLeftToRight; -webkit-animation-duration:5s; -moz-animation-duration:5s; animation-duration:5s; -webkit-animation-iteration-count:infinite; -moz-animation-iteration-count:infinite; animation-iteration-count:infinite; } .reverse{ -webkit-animation-direction:reverse; -moz-animation-direction:reverse; animation-direction:reverse; } .alternate{ -webkit-animation-direction:alternate; -moz-animation-direction:alternate; animation-direction:alternate; } .alternate-reverse{ -webkit-animation-direction:alternate-reverse; -moz-animation-direction:alternate-reverse; animation-direction:alternate-reverse; } @-webkit-keyframes FormLeftToRight{ 0%{left:0;} 100%{left:500px;} } @-moz-keyframes FormLeftToRight{ 0%{left:0;} 100%{left:500px;} } @keyframes FormLeftToRight{ 0%{left:0;} 100%{left:500px;} }
<!-- HTML代码 --> <body> <p>四种不同的顺序</p> <div class="box">normal</div> <div class="box reverse">reverse</div> <div class="box alternate">alternate</div> <div class="box alternate-reverse">alternate-reverse</div> </body>
效果:
四种不同的顺序
8)动画的状态(animation-play-state)
设置对象动画的状态
animation-play-state:running | paused
running:运动
paused:暂停
例子 源代码:
/* CSS代码 */ .state{ width:100px; height:100px; background:#000; position:relative; -webkit-animation-name:FromLeftToRight; -webkit-animation-duration:3s; -webkit-animation-iteration-count:infinite; -moz-animation-name:FromLeftToRight; -moz-animation-duration:3s; -moz-animation-iteration-count:infinite; animation-name:FromLeftToRight; animation-duration:3s; animation-iteration-count:infinite; } .state:hover{ -webkit-animation-play-state:paused; -moz-animation-play-state:paused; animation-play-state:paused; } @-webkit-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} } @-moz-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} } @keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} }
<!-- HTML代码 --> <body> <p>鼠标移动到矩形上可以暂停动画</p> <div class="state"></div> </body>
效果:
鼠标移动到矩形上可以暂停动画
9)动画时间之外的状态(animation-fill-mode)
设置对象动画时间之外的状态
animation-fill-mode : none | forwards | backwards | both
none:默认值。不设置对象动画之外的状态
forwards:设置对象状态为动画结束时的状态
backwards:设置对象状态为动画开始时的状态
both:设置对象状态为动画结束或开始的状态
例子 源代码:
/* CSS代码 */ .mode{ width:100px; height:100px; background:#000; position:relative; -webkit-animation-name:FromLeftToRight; -webkit-animation-duration:3s; -webkit-animation-fill-mode:forwards; -moz-animation-name:FromLeftToRight; -moz-animation-duration:3s; -moz-animation-fill-mode:forwards; animation-name:FromLeftToRight; animation-duration:3s; animation-fill-mode:forwards; } @-webkit-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} } @-moz-keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} } @keyframes FromLeftToRight{ 0% {left:0;} 100% {left:500px;} }
<!-- HTML代码 --> <body> <p>请按F5刷新动画(动画结束后停在结束位置)</p> <div class="mode"></div> </body>
效果:
请按F5刷新动画(动画结束后停在结束位置)
10)动画复合属性(animation)
通过 animation ,我们能够创建自定义动画,这可以在许多网页中取代动画图片gif、Flash 动画以及 JavaScript。
animation:<animation-name> || <animation-duration> || <animation-timing-function> || <animation-delay> || <animation-iteration-count> || <animation-direction> || <animation-fill-mode> || <animation-play-state> [ ,*]
利用学过的动画样式,制作一个下滑菜单栏
源代码:
/* CSS代码 */ .dropmenu{ width:100px; height:30px; line-height:30px; text-align:center; background:green; border-radius:10px; overflow:hidden; } .dropmenu a{ font-family:"微软雅黑"; font-size:18px; color:#fff; text-decoration:none; } .dropmenu ul{ list-style-type:none; padding:0; margin:0; } .dropmenu ul li{ background:#808080; } .dropmenu:hover{ -webkit-animation-name:SlideDown; -moz-animation-name:SlideDown; animation-name:SlideDown; -webkit-animation-duration:1s; -moz-animation-duration:1s; animation-duration:1s; -webkit-animation-fill-mode:forwards; -moz-animation-fill-mode:forwards; animation-fill-mode:forwards; } @-webkit-keyframes SlideDown{ 0% {height:30px;} 100% {height:155px;} } @-moz-keyframes SlideDown{ 0% {height:30px;} 100% {height:155px;} } @keyframes SlideDown{ 0% {height:30px;} 100% {height:155px;} }
<!-- HTML代码 --> <body> <div class="dropmenu"> <a href="###">菜单栏</a> <ul> <li><a href="###">AAA</a></li> <li><a href="###">AAA</a></li> <li><a href="###">AAA</a></li> <li><a href="###">AAA</a></li> </ul> </div> </body>
效果: