试一试 - JavaScript Reference event_animation

<!DOCTYPE html>
<html>
<head>
<style>
#myDIV {
   margin: 25px;
   width: 550px;
   height: 100px;
   background: orange;
   position: relative;
   font-size: 20px;
   text-align: center;
   -webkit-animation: mymove 4s infinite; /* Chrome, Safari, Opera */
   animation: mymove 4s infinite;
}

/* Chrome, Safari, Opera */
@-webkit-keyframes mymove {
   from {top: 0px;}
   to {top: 200px;}
}

@keyframes mymove {
   from {top: 0px;}
   to {top: 200px;}
}
</style>
</head>
<body>

<p>This example uses the addEventListener() method to attach an "animationstart" and "animationiteration" event to a DIV element.</p>

<p>When the animation is repeated, the background color of DIV will be light blue.</p>

<p>In this example, the elapsedTime property returns the number of seconds the <b>repeated animation</b> has been running:</p>

<p><strong>Note:</strong> The elapsedTime property is not supported in IE9 and earlier versions.</p>

<div id="myDIV">The animation has started</div>

<script>
var x = document.getElementById("myDIV");

// Code for Chrome, Safari and Opera
x.addEventListener("webkitAnimationIteration", myRepeatFunction);

// Standard syntax
x.addEventListener("animationiteration", myRepeatFunction);

function myRepeatFunction(event) {
   this.style.backgroundColor = "lightblue";
   this.innerHTML = "Elapsed time: " + event.elapsedTime + " seconds";
}
</script>

</body>
</html>

/* Chrome, Safari, Opera */
@-webkit-keyframes mymove {
    from {top: 0px;}
    to {top: 200px;}
}

@keyframes mymove {
    from {top: 0px;}
    to {top: 200px;}
}
</style>
</head>
<body>

<p>This example uses the addEventListener() method to attach an "animationstart" and "animationiteration" event to a DIV element.</p>

<p>When the animation is repeated, the background color of DIV will be light blue.</p>

<p>In this example, the elapsedTime property returns the number of seconds the <b>repeated animation</b> has been running:</p>

<p><strong>Note:</strong> The elapsedTime property is not supported in IE9 and earlier versions.</p>

<div id="myDIV">The animation has started</div>

// Code for Chrome, Safari and Opera
x.addEventListener("webkitAnimationIteration", myRepeatFunction);

// Standard syntax
x.addEventListener("animationiteration", myRepeatFunction);

function myRepeatFunction(event) {
    this.style.backgroundColor = "lightblue";
    this.innerHTML = "Elapsed time: " + event.elapsedTime + " seconds";
}
</script>

</body>
</html>