<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<style>
div{width:100px;height:100px;background:red;filter:alpha(opacity=100);opacity:1;}
</style>
<script>
function getStyle(obj,attr){
return obj.currentStyle ? obj.currentStyle[attr]:getComputedStyle(obj)[attr];
}
function perfectStartMove(obj,json){
clearInterval(obj.timer);
obj.timer = setInterval(function(){
var bStop = true;
for(var attr in json){
if(attr == 'opacity'){
var iCur = parseInt(parseFloat(getStyle(obj,attr))*100);
}else{
var iCur = parseInt(getStyle(obj,attr));
}
var speed = (json[attr]-iCur)/8;
speed = speed >0 ? Math.ceil(speed):Math.floor(speed);
if(iCur != json[attr]){
bStop = false;
}
if(attr == 'opacity'){
obj.style.filter = 'alpha(opacity='+(iCur+speed)+');';
obj.style[attr] = (iCur+speed)/100;
}else{
obj.style[attr] = iCur+speed+'px';
}
}
if(bStop){
clearInterval(obj.timer);
}
},30);
}
window.onload = function(){
var arrInput = document.getElementsByTagName('input')[0];
var arrDiv = document.getElementsByTagName('div')[0];
var onOff = true;
arrInput.onclick = function(){
if(onOff){
perfectStartMove(arrDiv,{width:300,height:300,opacity:30});
}else{
perfectStartMove(arrDiv,{width:100,height:100,opacity:100});
}
onOff = !onOff;
};
};
</script>
</head>
<body>
<input type='button' value = '开始运动'/>
<div></div>
</body>
</html>
