getStyle 和 startMove

 1 function getStyle(obj,attr){
 2             if(obj.currentStyle){
 3                 return obj.currentStyle[attr]
 4             }else{
 5                 return getComputedStyle(obj)[attr]
 6             }
 7         }
 8         function startMove(obj,json,fn){
 9             clearInterval(obj.timer);
10             obj.timer=setInterval(function(){
11                 var stops=true;
12                 for(var name in json){
13                     var target=parseInt(parseFloat(json[name]));
14                     var cur=parseInt(parseFloat(getStyle(obj,name)));
15                     var speed=(target-cur)/30;
16                     speed=speed>0?Math.ceil(speed):Math.floor(speed);
17                     obj.style[name]=speed+cur+"px";
18                     if(cur!=target){
19                         stops=false;
20                     }
21                 }
22                 if(stops){
23                     clearInterval(obj.timer);
24                     if(fn){
25                         fn()
26                     }
27                 }
28             },20)
29         }