Summary of new features of CSS3 (Animation)_html/css_WEB-ITnose

Animation is one of the highlights of CSS3.//

Specify @keyframe through the animation attribute to complete keyframe animation;

@keyframe usage :　

@keyframes name {  0% { top: 0; }/*0%可用from关键字替代*/  50% { top: 10px; }  100% { top: 0; }/*100%可用to关键字替代*/}

Since it is CSS3, there are various prefixes as expected:

--pictures from MDN, keyframes in CSS

Multiple attributes can be filled in a single frame, and they do not need to be consistent, such as:

@-webkit-keyframes identifier {  from { top: 0; }  50% { top: 10px;background-color:red; }  to { top: 20px;color:red; } }/*这是一个完全有效的关键帧定义*/

There are a few points to note:

in key frames Valid attributes are animatable attributes; if a non-animable attribute appears, the attribute will be ignored and will not affect the animation of other attributes,

If the attribute is followed by !important, the attribute will be ignored,

If a key frame is defined repeatedly, the frame defined later will be taken,

@-webkit-keyframes identifier { from { top: 0; }  50% {    top: 10px; /*该属性会动画*/    background-color:red !important; /*因为有!important字样,所以该条将被忽略*/    text-align:center; /*由于该属性不为可动画属性,因此也被忽略*/}  to { top: 20px;color:red; }   100% {color:green; } /*由于to关键字表示100%,所以该动画只会执行改变颜色为green,而to所对应的属性全部被忽略*/}

The frame number range is 0%-100%, and those that do not fall into this range will be ignored ( After experiments, the keyframe definition can be done out of order and can be executed correctly, but the readability is not very good);

Animation usage:

animation-name: Set the name of the animation, that is The logo followed by @keyframe;

animation-duration: the time it takes to set the animation, // these two are required attributes, the first one is not explained, the reason why the second one is required is that the default value is 0s, 0s will not produce animation effects, so it is required;

animation-timing-function: Set the speed curve of animation, the default value is ease, there are several optional values, you can pass cubic-bezier Functions are customizable. Here are some defined functions that can be used directly, such as teleportation array;

animation-delay: Set the waiting time before the animation starts, the default is 0s;

animation-iteration-count: Set the number of animation executions, the default is 1, use the infinite keyword to make the animation infinite loop;

animation-direction: Set the animation to be executed in reverse order after execution, the default is normal, use alternate Keyword turns on reverse execution // It will only be activated when the animation-iteration-count value is infinite. The time consumed by reverse execution is the time set by animation-duration;

animation-play-state: Set the current state of animation , the default is running, which is the execution state. It can be set to paused to pause.

animation-fill-mode: Set the state after the animation is executed (restore (none), keep the first frame (backwards) and keep The last frame (forwards), there is also a both value MDN said it is backwards and forwards at the same time, forgive me for not trying out the difference between it and forwards...,)

//Set the animation-iteration-count value When it is infinite, the attribute will be invalid;

The abbreviation of animation has particularly strict order requirements. The specifications are as follows:

animation:name duration timing-function delay iteration-count direction play -state fill-mode;

Be careful when using:

Various prefixes... If transform is used in @keyframe, it also needs to be prefixed, such as:

@-webkit-keyframe demo {    from {-webkit-transform:rotate(7deg);}      to {-webkit-transform:rotate(14deg);}  }

Some reference documents:

MDN’s animation

Keyframes in CSS3

W3School’s Animation attribute

W3School’s @Keyframe rules