Javascript实现的类似Google的Div拖动效果代码

JScript 文件： 
//检测浏览器 MSIE Firefox 
var ie=false,moz=false; 
(function() 
{//check the browser 
var userAgent=navigator.userAgent; 
if(userAgent.indexOf("MSIE")!=-1) 
ie=true; 
else if(userAgent.indexOf("Firefox")!=-1) 
moz=true; 
})(); 
//通过ID获得对象 
function $E_ID(idString) 
{ 
return document.getElementById(idString); 
} 
//通过Name获得对象 
function $Es_Tag(tagName) 
{ 
return document.getElementsByTagName(tagName); 
} 
//获得对象绝对位置 obj.offsetparent 
function $GetInfo(o) 
{ 
var to=new Object(); 
to.left=to.right=to.top=to.bottom=0; 
var twidth=o.offsetWidth; 
var theight=o.offsetHeight; 
while(o) 
{ 
to.left+=o.offsetLeft; 
to.top+=o.offsetTop; 
o=o.offsetParent; 
} 
to.right=to.left+twidth; 
to.bottom=to.top+theight; 
return to; 
} 
//鼠标点击对象确发事件 
function $hitTest(obj,event) 
{ 
obj=$GetInfo(obj); 
var x=event.clientX; 
var y=event.clientY; 
if((x>=obj.left&&x<=obj.right)&&(y>=obj.top&&y<=obj.bottom)) 
　return true; 
else 
　return false; 
} 
function Drag(event) 
{ 
this.dragged=false; 
this.ao=null; 
this.tdiv=null; 
this.fixLeft=0; 
this.fixTop=0; 
this.lastX=event.clientX; 
this.lastY=event.clientY; 
Drag.mm=null; 
this.dragStart=function(event) 
{ 
this.ao=ie?event.srcElement:(moz?event.target:null); 
if(ie) 
document.body.onselectstart=function() 
{ 
　　return false 
　　} 
if(moz&&this.ao.nodeType==3) 
　this.ao=this.ao.parentNode; 
if(this.ao.tagName=="TD"||this.ao.tagName=="TR") 
　this.ao=this.ao.offsetParent.parentNode; 
else 
　return; 
if(this.ao.className!="dragdiv") 
　return; 
this.tdiv=$E_ID("tmpdiv"); 
this.tdiv.style.visibility="visible"; 
this.tdiv.style.filter="alpha(opacity=70)"; 
if(ie) 
　this.tdiv.filters.alpha.opacity=70; 
this.tdiv.style.opacity=0.7; 
this.tdiv.style.zIndex=100; 
this.tdiv.innerHTML=this.ao.innerHTML; 
this.tdiv.style.width=this.ao.offsetWidth+"px"; 
this.tdiv.style.height=this.ao.offsetHeight+"px"; 
this.tdiv.style.top=$GetInfo(this.ao).top+"px"; 
this.tdiv.style.left=$GetInfo(this.ao).left+"px"; 
this.fixTop=parseInt($GetInfo(this.tdiv).top); 
this.fixLeft=parseInt($GetInfo(this.tdiv).left); 
this.dragged=true; 
} 
this.onDrag=function(event) 
{ 
if((!this.dragged)||this.ao==null)return; 
var tX=event.clientX; 
var tY=event.clientY; 
this.tdiv.style.left=parseInt(this.fixLeft+tX-this.lastX-document.body.scrollLeft)+"px"; 
this.tdiv.style.top=parseInt(this.fixTop+tY-this.lastY-document.body.scrollTop)+"px"; 
for(var m=0;m<$E_ID("root").rows.length;m++) 
{ 
var rootCells=$E_ID("root").rows[m].cells; 
for(var i=0;i<rootCells.length;i++) 
{ 
if($hitTest(rootCells[i],event)) 
{ 
if(rootCells[i].hasChildNodes()) 
{ 
for(var j=0;j<rootCells[i].childNodes.length;j++) 
{ 
if($hitTest(rootCells[i].childNodes[j],event)) 
{ 
rootCells[i].insertBefore(this.ao,rootCells[i].childNodes[j]); 
break; 
} 
} 
if(j==rootCells[i].childNodes.length) 
{ 
rootCells[i].appendChild(this.ao);break; 
} 
break; 
} 
else 
{ 
rootCells[i].appendChild(this.ao); 
break; 
} 
} 
} 
} 
} 
this.dragEnd=function() 
{ 
if(this.dragged) 
{ 
this.dragged=false; 
Drag.mm=this.repos(150,15,this); 
this.ao=null; 
} 
if(ie)document.body.onselectstart=function(){return true} 
} 
this.repos=function(aa,ab,obj) 
{ 
if(ie)var f=obj.tdiv.filters.alpha.opacity; 
else if(moz)var f=obj.tdiv.style.opacity*100; 
var kf=f/ab; 
var tl=parseInt($GetInfo(obj.tdiv).left); 
var tt=parseInt($GetInfo(obj.tdiv).top); 
var kl=(tl-$GetInfo(obj.ao).left)/ab; 
var kt=(tt-$GetInfo(obj.ao).top)/ab; 
return setInterval(function(){ 
if(ab<1) 
{ 
clearInterval(Drag.mm); 
obj.tdiv.style.visibility="hidden"; 
obj.tdiv.style.zIndex=""; 
return; 
} 
ab--; 
tl-=kl; 
tt-=kt; 
f-=kf; 
obj.tdiv.style.left=parseInt(tl)+"px"; 
obj.tdiv.style.top=parseInt(tt)+"px"; 
if(ie)obj.tdiv.filters.alpha.opacity=f; 
else if(moz)obj.tdiv.style.opacity=f/100; 
},aa/ab ); 
} 
} 
var tDrag=null; 
function init(event) 
{ 
// alert(event.target.innerHTML); 
tDrag=new Drag(event); 
tDrag.dragStart(event); 
} 
function move(event) 
{ 
if(tDrag!=null)tDrag.onDrag(event); 
} 
function end() 
{ 
if(tDrag!=null){ 
tDrag.dragEnd(); 
tDrag=null; 
} 
} 
Asp.net文件： 
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %> 
<!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 > 
<title>Div拖动</title> 
<style type="text/css"> 
<!-- 
.dragHeader 
{ 
background-color:#e5eef9; 
border-top:1px solid #0066FF; 
height: 20px; 
cursor: move; 
font-weight: bold; 
} 
body 
{ 
font-family: Arial, Helvetica, sans-serif; 
font-size: 12px; 
} 
#root td 
{ 
vertical-align:top; 
border:1px dotted #666666; 
} 
#tmpdiv 
{ 
position: absolute; 
} 
.dragdiv 
{ 
} 
.style1 
{ 
color: #FFFFFF; 
font-weight: bold; 
font-size: 36px; 
} 
--> 
</style> 
<script type="text/javascript" src="DivDrag.js"></script> 
</head> 
<body onMouseDown="init(event)" onMouseUp="end()" onMouseMove="move(event)" > 
<script language="javascript" type="text/javascript" > 
document.write("<div id='tmpdiv'><\/div>"); 
</script> 
<table id="root" style="width:600px;height:300px" cellpadding="0" cellspacing="1" > 
<tr style="height:150px;width:600px"> 
<td style="width:200px; height: 50px;"> 
<div class="dragdiv" id="div1" > 
<table style="height:100%;width:100%" border ="0"> 
<tr> 
<td> 
<input id="Button1" type="button" value="button" /> 
可移动DIV1<br> 
点击即可开始拖动! 
</td> 
</tr> 
</table> 
</div> 
</td> 
<td style="width:200px; height: 50px;"> 
<div class="dragdiv" id="div2" 
<table style="height:100%;width:100%" border ="0"> 
<tr> 
<td> 
<input id="Button2" type="button" value="button" /> 
可移动DIV2<br> 
点击即可开始拖动! 
</td> 
</tr> 
</table> 
</div> 
</td> 
<td style="width:200px; height: 50px;"> 
<div class="dragdiv" id="div3" 
<table style="height:100%;width:100%" border ="0"> 
<tr> 
<td> 
<input id="Button3" type="button" value="button" /> 
可移动DIV3<br> 
点击即可开始拖动! 
</td> 
</tr> 
</table> 
</div> 
</td> 
</tr> 
<tr style="height:150px;width:600px"> 
<td style="width:200px; height: 50px;"> 
</td> 
<td style="width:200px; height: 50px;"> 
</td> 
<td style="width:200px; height: 50px;"> 
</td> 
</tr> 
<tr style="height:150px;width:600px"> 
<td style="width:200px; height: 50px;"> 
</td> 
<td style="width:200px; height: 50px;"> 
</td> 
<td style="width:200px; height: 50px;"> 
</td> 
</tr> 
</table> 
</body> 
</html>