Learn CSS3 animation (animation)

　 CSS3 has a lot of advanced functions, such as 3D effects, animations, multiple columns, etc. Today I will write an article to record how to write an animation using CSS3.

I have to say something ugly first, IE9 and below versions do not support CSS3 animation (if you really want to implement it, you can consider using js, but the effect is not very good). Chrome and Safafi recommend adding the prefix -webkit- for forward compatibility with older versions.

Today I will simply make an animation.

First, simply draw a div and then add a background image.

<span style="color: #0000ff;"><</span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><</span><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="demo"</span><span style="color: #0000ff;">></span><span style="color: #000000;">
        我是demo
    </span><span style="color: #0000ff;"></</span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></</span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>

<span style="color: #800000;">.demo</span>{<span style="color: #ff0000;">
    width</span>:<span style="color: #0000ff;"> 120px</span>;<span style="color: #ff0000;">
    height</span>:<span style="color: #0000ff;"> 120px</span>;<span style="color: #ff0000;">
    margin</span>:<span style="color: #0000ff;"> 100px auto</span>;<span style="color: #ff0000;">
    background</span>:<span style="color: #0000ff;"> url(img/demo.jpg) no-repeat</span>;
}

An ordinary DIV will appear, as shown on the right:

Then let’s make it move

First write a method that describes how this picture should move

<span style="color: #800000;">@keyframes run_animation</span>{      <span style="color: #ff0000;">
    from {
        transform</span>:<span style="color: #0000ff;"> rotatez(0deg)</span>;
    }<span style="color: #800000;">
    to </span>{<span style="color: #ff0000;">
        transform</span>:<span style="color: #0000ff;"> rotatez(360deg)</span>;
    }<span style="color: #800000;">
}</span>

This animation_run is the name of this method. You need to associate the name to the relevant element later.

from describes the starting state of the animation, and to is the end state of the animation.

So this method is to rotate an element 360 degrees in a clockwise direction, which is very simple.

from to often cannot meet our daily development needs, so there is still this way of writing

@keyframes run_animation{
    0%{<br />　　　　 transform:rotatex(0deg);<br />　　 }
    16%{
        transform: rotatey(-90deg);
    }
    33%{
        transform: rotatey(-90deg) rotatez(135deg);
    }
    50%{
        transform: rotatey(225deg) rotatez(135deg);
    }
    66%{
        transform: rotatey(135deg) rotatex(135deg);
    }
    83%{
        transform: rotatex(135deg);
    }<br />　　100%{<br />　　　　 transform: rotatex(0deg);<br />　　}
}

This description allows the animation to have richer and cooler actions. The dynamics of the element at each stage are described by percentages. 0% is the from mentioned above, and 100% is to. Actually, this is very simple, right~

Animation is so easy to write. Next we attach the animation to our image.

<span style="color: #800000;">.demo</span>{<span style="color: #ff0000;">
    width</span>:<span style="color: #0000ff;"> 120px</span>;<span style="color: #ff0000;">
    height</span>:<span style="color: #0000ff;"> 120px</span>;<span style="color: #ff0000;">
    margin</span>:<span style="color: #0000ff;"> 100px auto</span>;<span style="color: #ff0000;">
    animation</span>:<span style="color: #0000ff;"> run_animation 12s linear infinite</span>; /*关联动画名称，定义动画时长，动画播放速度曲线，播放次数*/<span style="color: #ff0000;">
    background</span>:<span style="color: #0000ff;"> url(img/demo.jpg) no-repeat 100%</span>;
}

With such a simple code, the picture can move according to the method we defined.

If you find that the animation is not moving now, it may be one of the following reasons:

1. The animation name does not match the name defined by @keyframes;

2. The animation playback duration is not defined. The default is 0S, which means no animation is played. The above code defines 12S;

3. Run this code in IE9 and below browsers, IE9 and below do not support CSS3 animation;

4. The animation method is incorrectly defined. The style is the same in each stage of the method definition. Like below

<span style="color: #800000;">@keyframes run_animation</span>{<span style="color: #ff0000;">
    0%{
        transform</span>:<span style="color: #0000ff;"> rotatez(90deg)</span>;
    }<span style="color: #800000;">
    50%</span>{<span style="color: #ff0000;">
        transform</span>:<span style="color: #0000ff;"> rotatez(90deg)</span>;
    }<span style="color: #800000;">
   100%</span>{<span style="color: #ff0000;">
        transform</span>:<span style="color: #0000ff;"> rotatez(90deg)</span>;
    }<span style="color: #800000;">
}</span>

Okay, now the animation should be moving. Let’s talk about the other options in the animation:

1.animation-iteration-count: The number of times the animation is played, write down how many times you want to play it. I have used it infinite times here and it’s infinite

2.animation-timing-function: animation speed curve. This speed curve is a bit complicated and involves a Bessel function. If you don’t want to explore Bezier in depth, just use the ready-made linear, ease, ease-in, ease-out, and ease-in-out. If you know Bezier, you can use cubic-bezier(n,n,n,n). This is more advanced and I think it is a powerful tool in the field of pretense.

3.animation-delay: Animation can be played with delay, and the parameters are also n S. Unlike animation-duration, animation-duration is the duration of animation playback.

The above attributes can all be abbreviated to animation, just like my chestnut above.

There are also reverse playback and pause attributes that I won’t talk about. If necessary, you can go to http://www.w3school.com.cn/css3/css3_animation.asp or

https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Animations/Using_CSS_animations

If you still have any questions or suggestions, you can communicate more. It is an original article. The writing style is limited and the talent is shallow. If there is anything wrong in the article, I hope you will tell me ending~