FCC---Change Animation Timing with Keywords--两个小球从A都B,相同循环时间 duration, 不同的速度 speed
In CSS animations, the animation-timing-function
property controls how quickly an animated element changes over the duration of the animation.
If the animation is a car moving from point A to point B in a given time (your animation-duration
), the animation-timing-function
says how the car accelerates and decelerates over the course of the drive.
There are a number of predefined keywords available for popular options. For example, the default value is ease
, which starts slow, speeds up in the middle, and then slows down again in the end.
Other options include ease-out
, which is quick in the beginning then slows down, ease-in
, which is slow in the beginning, then speeds up at the end, or linear
, which applies a constant animation speed throughout.
练习题目:
For the elements with id of ball1
and ball2
, add an animation-timing-function
property to each, and set #ball1
to linear
, and #ball2
to ease-out
.
Notice the difference between how the elements move during the animation but end together, since they share the same animation-duration
of 2 seconds.
练习代码:
1 <style> 2 3 .balls { 4 border-radius: 50%; 5 background: linear-gradient( 6 35deg, 7 #ccffff, 8 #ffcccc 9 ); 10 position: fixed; 11 width: 50px; 12 height: 50px; 13 margin-top: 50px; 14 animation-name: bounce; 15 animation-duration: 2s; 16 animation-iteration-count: infinite; 17 } 18 #ball1 { 19 left:27%; 20 animation-timing-function: linear; 21 } 22 #ball2 { 23 left:56%; 24 animation-timing-function: ease-out; 25 } 26 27 @keyframes bounce { 28 0% { 29 top: 0px; 30 } 31 100% { 32 top: 249px; 33 } 34 } 35 36 </style> 37 38 <div class="balls" id="ball1"></div> 39 <div class="balls" id="ball2"></div>
效果如下:
注意,因为循环时间相同,所以2个小球不同速率,但同一时间结束