CSS3,我们可以创建动画,它可以取代许多网页动画图像,Flash动画,和JAVAScripts。
CSS3 @keyframes 规则
要创建CSS3动画,你将不得不了解@keyframes规则。
@keyframes规则是创建动画。 @keyframes规则内指定一个CSS样式和动画将逐步从目前的样式更改为新的样式。
@keyframes myfirst
{
from {background: red;}
to {background: yellow;}
}
@-webkit-keyframes myfirst /* Safari 与 Chrome */
{
from {background: red;}
to {background: yellow;}
}
CSS3 动画
当在 @keyframes 创建动画,把它绑定到一个选择器,否则动画不会有任何效果。
指定至少这两个CSS3的动画属性绑定向一个选择器:
- 规定动画的名称
- 规定动画的时长
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>css3动画</title> <style type="text/css"> * { margin: 0; padding: 0; } div { width: 100px; height: 100px; background: red; animation: myfirst 5s; /*规定动画的名称:myfirst 规定动画的时长: 5s*/ -webkit-animation: myfirst 5s; } @-webkit-keyframes myfirst { from {background: red} to {background: yellow} } @keyframes myfirst { form {background: red} to {background: yellow} } </style> </head> <body> <div></div> </body> </html>
您必须定义动画的名称和动画的持续时间。如果省略的持续时间,动画将无法运行,因为默认值是0。
CSS3动画是什么?
动画是使元素从一种样式逐渐变化为另一种样式的效果。
您可以改变任意多的样式任意多的次数。
请用百分比来规定变化发生的时间,或用关键词 "from" 和 "to",等同于 0% 和 100%。
0% 是动画的开始,100% 是动画的完成。
为了得到最佳的浏览器支持,您应该始终定义 0% 和 100% 选择器。
当动画为 25% 及 50% 时改变背景色,然后当动画 100% 完成时再次改变:
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>css3 过渡</title> <style type="text/css"> * { margin: 0; padding: 0; } div { width: 100px; height: 100px; background: red; -moz-animation: myfirst 5s; /* Firefox*/ -webkit-animation: myfirst 5s; /* Safari and Chrome*/ -o-animation: myfirst 5s; /* Opera */ animation: myfirst 5s; } @-moz-keyframes myfirst { /* Firefox*/ 0% {background: red;} 25% {background: yellow;} 50% {background: blue;} 100% {background: green;} } @-webkit-keyframes myfirst { /* Safari and Chrome*/ 0% {background: red;} 25% {background: yellow;} 50% {background: blue;} 100% {background: green;} } @-o-keyframes myfirst { /* Opera */ 0% {background: red;} 25% {background: yellow;} 50% {background: blue;} 100% {background: green;} } @keyframes myfirst { 0% {background: red;} 25% {background: yellow;} 50% {background: blue;} 100% {background: green;} } </style> </head> <body> <div></div> </body> </html>
改变背景色和位置:
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>css3 过渡</title> <style type="text/css"> * { margin: 0; padding: 0; } div { position: relative; width: 100px; height: 100px; background: red; -moz-animation: myfirst 5s; /* Firefox*/ -webkit-animation: myfirst 5s; /* Safari and Chrome*/ -o-animation: myfirst 5s; /* Opera */ animation: myfirst 5s; } @-moz-keyframes myfirst { /* Firefox*/ 0% {background: red; left: 0; top: 0;} 25% {background: yellow; left: 200px; top: 0;} 50% {background: blue; left: 200px; top: 200px;} 75% {background: green; left: 0; top: 200px;} 100% {background: red; left: 0; top: 0;} } @-webkit-keyframes myfirst { /* Safari and Chrome*/ 0% {background: red; left: 0; top: 0;} 25% {background: yellow; left: 200px; top: 0;} 50% {background: blue; left: 200px; top: 200px;} 75% {background: green; left: 0; top: 200px;} 100% {background: red; left: 0; top: 0;} } @-o-keyframes myfirst { /* Opera */ 0% {background: red; left: 0; top: 0;} 25% {background: yellow; left: 200px; top: 0;} 50% {background: blue; left: 200px; top: 200px;} 75% {background: green; left: 0; top: 200px;} 100% {background: red; left: 0; top: 0;} } @keyframes myfirst { 0% {background: red; left: 0; top: 0;} 25% {background: yellow; left: 200px; top: 0;} 50% {background: blue; left: 200px; top: 200px;} 75% {background: green; left: 0; top: 200px;} 100% {background: red; left: 0; top: 0;} } </style> </head> <body> <div></div> </body> </html>
CSS3的动画属性
下面的表格列出了 @keyframes 规则和所有动画属性:
属性 | 描述 | CSS |
---|---|---|
@keyframes | 规定动画。 | 3 |
animation | 所有动画属性的简写属性,除了 animation-play-state 属性。 | 3 |
animation-name | 规定 @keyframes 动画的名称。 | 3 |
animation-duration | 规定动画完成一个周期所花费的秒或毫秒。默认是 0。 | 3 |
animation-timing-function | 规定动画的速度曲线。默认是 "ease"。 | 3 |
animation-delay | 规定动画何时开始。默认是 0。 | 3 |
animation-iteration-count | 规定动画被播放的次数。默认是 1。 | 3 |
animation-direction | 规定动画是否在下一周期逆向地播放。默认是 "normal"。 | 3 |
animation-play-state | 规定动画是否正在运行或暂停。默认是 "running"。 | 3 |
将逐个属性再重新写一遍
@keyframes 规定动画从一个样式到另外一种样式的效果
@keyframes myfirst {
from {background: red;}
to {background: orange;}
}
from代表0% to代表100% 从0%到100%期间背景颜色由红色变成橙色,注意必须指定动画一个周期的时间 (默认为0),所以不写动画时间就看不出效果
animation: myfirst 5s
设置时间为5s 这样动画到结束需要5s时间
animaton
使用简写属性把 animation 绑定到一个<div> 元素:
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>css3 动画</title> <style type="text/css"> * { margin: 0; padding: 0; } div { position: relative; width: 200px; height: 200px; background: red; -webkit-transition: mymove 5s infinite; animation: mymove 5s infinite; } @-webkit-keyframes mymove { from {left: 0;} to {left: 200px;} } @keyframes mymove { from {left: 0;} to {left: 200px;} } </style> </head> <body> <div></div> </body> </html>
这个动画会重复执行下去
animation-name
为 @keyframes 动画指定一个名称并且规定动画完成一个周期所花费的秒或毫秒
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>css3 动画</title> <style type="text/css"> * { margin: 0; padding: 0; } div { position: relative; width: 100px; height: 100px; background: red; -webkit-animation-name: mymove; /* 指定名称 */ -webkit-animation-duration: 5s;/*规定动画完成一个周期所花费的秒*/ animation-name: mymove; animation-duration: 5s; } @-webkit-keyframes mymove { from {left: 0;} to {left: 200px;} } @keyframes mymove { from {left: 0;} to {left: 200px;} } </style> </head> <body> <div></div> </body> </html>
animation-ttiming-function
从开始到结束以相同的速度播放动画:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>css动画</title> <style type="text/css"> * { margin: 0; padding: 0; } div { width: 100px; height: 100px; background: red; position: relative; -webkit-animation: mymove 5s infinite; -webkit-timing-function: linear;/*开始到结束都用相同的速度*/ animation: mymove 5s infinite; animation-timing-function: linear; } @-webkit-keyframes mymove { from {left: 0} to {left: 200px} } @keyframes mymove { from {left: 0} to {left: 200px} } </style> </head> <body> <div></div> </body> </html>
animation-delay
规定动画何时开始。默认是 0。
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>css3 动画</title> <style type="text/css"> * { margin: 0; padding: 0; } div { position: relative; width: 100px; height: 100px; background: red; -webkit-animation: mymove 5s infinite; -webkit-animation-delay: 2s; animation-name: mymove 5s infinite; animation-delay: 2s; /*2s后进入动画*/ } @-webkit-keyframes mymove { from {left: 0;} to {left: 200px;} } @keyframes mymove { from {left: 0;} to {left: 200px;} } </style> </head> <body> <div></div> </body> </html>
animation-iteration-count属性
定义应该播放多少次动画
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>css3 动画</title> <style type="text/css"> * { margin: 0; padding: 0; } div { position: relative; width: 100px; height: 100px; background: red; -webkit-animation: mymove 5s ; -webkit-animation-iteration-count: 3; animation-name: mymove 5s; animation-iteration-count: 3; /*执行3次动画 infinite是无限播放*/ } @-webkit-keyframes mymove { from {left: 0;} to {left: 200px;} } @keyframes mymove { from {left: 0;} to {left: 200px;} } </style> </head> <body> <div></div> </body> </html>
animation-direction: alternate;
先执行一遍动画,然后再反向执行一遍动画:
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>css3 过渡</title> <style type="text/css"> * { margin: 0; padding: 0; } div { position: relative; width: 100px; height: 100px; background: red; -webkit-animation: mymove 5s infinite; -webkit-direction: alternate; animation-name: mymove 5s infinite; animation-direction: alternate; } @-webkit-keyframes mymove { from {left: 0; top: 0;} to {left: 200px; top: 40px;} } @keyframes mymove { from {left: 0; top: 0;} to {left: 200px; top: 40px;} } </style> </head> <body> <div></div> </body> </html>
暂停动画:
animation-play-staye
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>css3 动画</title> <style type="text/css"> * { margin: 0; padding: 0; } div { position: relative; width: 100px; height: 100px; background: red; -webkit-animation: mymove 5s; -webkit-animation-play-state: paused; animation-name: mymove 5s; animation-play-state: paused; /*暂停动画*/ } @-webkit-keyframes mymove { from {left: 0; top: 0;} to {left: 200px; top: 40px;} } @keyframes mymove { from {left: 0; top: 0;} to {left: 200px; top: 40px;} } </style> </head> <body> <div></div> </body> </html>