效果:打开页面时,出现一个大幅广告,过一段时间后,大幅广告缩小成一个小幅广告,宽度不变,高度变小,并且带有缩小动画。点击运行可看到效果。
[code]
<!DOCTYPE HTML PUBLIC"-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<style>
html,body{margin:0;font-size:12px}img{border:none}p{border-top:5px solid#660000;padding:40px;background:#999900;height:1500px;margin:0px}
</style>
<script>
var showAD = {
curve: function(t, b, c, d, s) {
if ((t /= d / 2) < 1) return c / 2 * t * t * t + b;
return c / 2 * ((t -= 2) * t * t + 2) + b
},
fx: function(from, to, playTime, onEnd) {
var Me = this,
who = this.adWrap,
position = 0,
changeVal = to – from,
curve = this.curve;
playTime = playTime / 10;
who.style.overflow = ‘hidden’;
function _run() {
if (position++<playTime) {
who.style.height = Math.max(1, Math.abs(Math.ceil(curve(position, from, changeVal, playTime)))) + "px";
setTimeout(_run, 10)
} else {
onEnd && onEnd.call(Me, to)
}
};
_run()
},
init: function(info) {
var Me = this,
loadImg = new Image;
loadImg.src = info.endImgURL;
window.onload=function() {
Me.endImgURL = info.endImgURL;
Me.img = document.getElementById(info.imgID);
Me.adWrap = document.getElementById(info.adWrapID);
var max = Me.img.height;
setTimeout(function() {
Me.fx(max, 0, 500,
function(x) {
this.img.src = this.endImgURL;
this.curve = function(t, b, c, d) {
if ((t /= d) < (1 / 2.75)) {
return c * (7.5625 * t * t) + b
} else if (t < (2 / 2.75)) {
return c * (7.5625 * (t -= (1.5 / 2.75)) * t + .75) + b
} else if (t < (2.5 / 2.75)) {
return c * (7.5625 * (t -= (2.25 / 2.75)) * t + .9375) + b
} else {
return c * (7.5625 * (t -= (2.625 / 2.75)) * t + .984375) + b
}
};
this.fx(0, this.img.height,600)
})
},
info.timeout || 1000)
};
}
};
showAD.init({
adWrapID: ‘ad_box_2009_04’,
imgID: ‘adImg’,
endImgURL: ‘http://www.aspprogram.cn/test/a.jpg’
});
</script>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312"></head>
<body>
<div id="ad_box_2009_04" style="background:BF0008">
<img src="http://www.aspprogram.cn/test/b.jpg" id="adImg" />
</div>
<p>正文</p>
</body>
</html>
[/code]