透明度动画
实现效果：当数遍移动到图片上时。图片发生渐变效果；当鼠标离开时，恢复原图效果。
解答：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>透明度动画</title>
<style type="text/css">
*{
margin:0;
padding:0;
}
#div1{
width:200px;
height:200px;
background:red;
filter:alpha(opacity:30);
opacity:0.3;
}
</style>
<script>
window.onload = function(){
var oDiv = document.getElementById('div1');
oDiv.onmouseover = function(){
startMove(100);
}
oDiv.onmouseout = function(){
startMove(30);
}
}
var timer = null;
var alpha = 30;
function startMove(iTarget){
var oDiv = document.getElementById('div1');
clearInterval(timer);
timer = setInterval(function(){
var speed = 0;
if(alpha > iTarget){
speed = -10;
}else{
speed = 10;
}
if(alpha == iTarget){
clearInterval(timer);
}else{
alpha = alpha + speed;
oDiv.style.filter = 'alpha(opacity:'+alpha+')';
oDiv.style.opacity = alpha/100;
}
},30)
}
</script>
</head>
<body>
<div id="div1"></div>
</body>
</html> 以上就是前端实践--JavaScript--动画（二）的内容，更多相关内容请关注PHP中文网（www.php.cn）！
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