Learn CSS3 animation (animation)-CSS Tutorial-php.cn

Learn CSS3 animation (animation)

高洛峰

Release： 2016-10-09 16:12:56

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

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.

<body>
    <div class="demo">
        我是demo    </div></body>

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.demo{
    width: 120px;
    height: 120px;
    margin: 100px auto;
    background: url(img/demo.jpg) no-repeat;
}

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An ordinary DIV comes out, as shown on the right: Learn CSS3 animation (animation)

Then we make it move

First write a method, which describes how this picture should move

@keyframes run_animation{      
    from {
        transform: rotatez(0deg);
    }
    to {
        transform: rotatez(360deg);
    }
}

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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 also 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>　　}
}

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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. In fact, this is very simple, right~

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

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

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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, and the default is 0S, that is, no Play animation. The above code definition is 12S;

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

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

@keyframes run_animation{
    0%{
        transform: rotatez(90deg);
    }
    50%{
        transform: rotatez(90deg);
    }
   100%{
        transform: rotatez(90deg);
    }
}

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

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

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.

I won’t talk about the properties of reverse playback and pause. 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_animation