javascript实现拖动层效果代码(符合标准且兼容IE,chrome,firefox)

实例代码一见：


代码如下:

<!DOCTYPE HTML>
<html>
<head>
<style type="text/css">
#main div{position:absolute;width:220px;height:150px;border:1px solid #999;}
</style>
<script type="text/javascript">
var a;
document.onmouseup = function() {
if (!a) return;
a = "";
};
document.onmousemove = function(d) {
if (!a) return;
d=d||event;
a.style.left = (d.clientX - b) + "px";
a.style.top = (d.clientY - c) + "px";
};
function $(o, e) {
a = o;
b = e.clientX - parseInt(a.style.left);
c = e.clientY - parseInt(a.style.top);
}
</script>
</head>
<body>
<div id="main">
<div style="left:100px;top:100px;background:#fc9;" onmousedown="$(this,event)">1</div>
<div style="left:400px;top:100px;background:#9cf;" onmousedown="$(this,event)">2</div>
<div style="left:700px;top:100px;background:#f9c;" onmousedown="$(this,event)">3</div>
<div style="left:100px;top:300px;background:#9fc;" onmousedown="$(this,event)">4</div>
<div style="left:400px;top:300px;background:#c9f;" onmousedown="$(this,event)">5</div>
<div style="left:700px;top:300px;background:#cf9;" onmousedown="$(this,event)">6</div>
</div>
</body>
</html>

效果：

#main div{position:absolute;width:220px;height:150px;border:1px solid #999;}

var a;
document.onmouseup = function() {
if (!a) return;
a = "";
};
document.onmousemove = function(d) {
if (!a) return;
d=d||event;
a.style.left = (d.clientX - b) + "px";
a.style.top = (d.clientY - c) + "px";
};
function $(o, e) {
a = o;
b = e.clientX - parseInt(a.style.left);
c = e.clientY - parseInt(a.style.top);
}

1

2

3

4

5

6

[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]

实例代码二见：

代码如下:

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<style type="text/css">
#test{width:200px; height:200px; background:pink; cursor:move; position:absolute; left:100px; top:100px}
</style>
</head>
<body>
<div id="test"></div>
<script type="text/javascript">
var obj=document.getElementById("test");
var b;
obj.onmousedown=function(e){
b=true;
var divLeft=parseFloat(window.getComputedStyle?window.getComputedStyle(obj,null).left:obj.currentStyle.left);
var divTop=parseFloat(window.getComputedStyle?window.getComputedStyle(obj,null).top:obj.currentStyle.top);
var e=e||event;
var divX=e.clientX-divLeft; //计算鼠标和div边框的距离
var divY=e.clientY-divTop;
document.onmousemove=function(e){
if(b){
var e=e||event; //兼容IE8及以下
obj.style.left=e.clientX-divX+"px";
obj.style.top=e.clientY-divY+"px";
}
}
}
document.onmouseup=function(){
b=false;
}
</script>
</body>
</html>

效果：

无标题文档

#test{width:200px; height:200px; background:pink; cursor:move; position:absolute; left:100px; top:100px}

var obj=document.getElementById("test");
var b;
obj.onmousedown=function(e){
b=true;
var divLeft=parseFloat(window.getComputedStyle?window.getComputedStyle(obj,null).left:obj.currentStyle.left);
var divTop=parseFloat(window.getComputedStyle?window.getComputedStyle(obj,null).top:obj.currentStyle.top);
var e=e||event;
var divX=e.clientX-divLeft; //计算鼠标和div边框的距离
var divY=e.clientY-divTop;
document.onmousemove=function(e){
if(b){
var e=e||event; //兼容IE8及以下
obj.style.left=e.clientX-divX+"px";
obj.style.top=e.clientY-divY+"px";
}
}
}
document.onmouseup=function(){
b=false;
}

[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]

实例代码三见（拖动把柄）：

无标题文档

*{margin:0;padding:0}
#testBox{ width:300px; height:300px; background:red; position:absolute; left:0; top:0}
#test{width:200px; height:200px; background:pink; cursor:move; margin:30px}

在这里才能移动

var obj=document.getElementById("test");
var objBox=document.getElementById("testBox");
var b;
obj.onmousedown=function(e){
b=true;
var divLeft=parseFloat(window.getComputedStyle?window.getComputedStyle(objBox,null).left:objBox.currentStyle.left);
var divTop=parseFloat(window.getComputedStyle?window.getComputedStyle(objBox,null).top:objBox.currentStyle.top);
var e=e||event;
var divX=e.clientX-divLeft; //计算鼠标和div边框的距离
var divY=e.clientY-divTop;
document.onmousemove=function(e){
if(b){
var e=e||event; //IE8及以下浏览器得写这句
objBox.style.left=e.clientX-divX+"px";
objBox.style.top=e.clientY-divY+"px";
}
}
}
document.onmouseup=function(){
b=false;
}

[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]