比较精简的Javascript拖动效果函数代码

拖动效果函数演示 by Longbill.cn

body
{
font-size:12px;
color:#333333;
border : 0px solid blue;
}
div
{
position : absolute;
background-color : #c3d9ff;
margin : 0px;
padding : 5px;
border : 0px;
width : 100px;
height:100px;
}

function drag(o,s)
{
if (typeof o == "string") o = document.getElementById(o);
o.orig_x = parseInt(o.style.left) - document.body.scrollLeft;
o.orig_y = parseInt(o.style.top) - document.body.scrollTop;
o.orig_index = o.style.zIndex;

o.onmousedown = function(a)
{
this.style.cursor = "move";
this.style.zIndex = 10000;
var d=document;
if(!a)a=window.event;
var x = a.clientX+d.body.scrollLeft-o.offsetLeft;
var y = a.clientY+d.body.scrollTop-o.offsetTop;
//author: www.longbill.cn
d.ondragstart = "return false;"
d.onselectstart = "return false;"
d.onselect = "document.selection.empty();"

if(o.setCapture)
o.setCapture();
else if(window.captureEvents)
window.captureEvents(Event.MOUSEMOVE|Event.MOUSEUP);

d.onmousemove = function(a)
{
if(!a)a=window.event;
o.style.left = a.clientX+document.body.scrollLeft-x;
o.style.top = a.clientY+document.body.scrollTop-y;
o.orig_x = parseInt(o.style.left) - document.body.scrollLeft;
o.orig_y = parseInt(o.style.top) - document.body.scrollTop;
}

d.onmouseup = function()
{
if(o.releaseCapture)
o.releaseCapture();
else if(window.captureEvents)
window.captureEvents(Event.MOUSEMOVE|Event.MOUSEUP);
d.onmousemove = null;
d.onmouseup = null;
d.ondragstart = null;
d.onselectstart = null;
d.onselect = null;
o.style.cursor = "normal";
o.style.zIndex = o.orig_index;
}
}

if (s)
{
var orig_scroll = window.onscroll?window.onscroll:function (){};
window.onscroll = function ()
{
orig_scroll();
o.style.left = o.orig_x + document.body.scrollLeft;
o.style.top = o.orig_y + document.body.scrollTop;
}
}
}

div1:我可以被拖动

div2:来拖我呀

div3:我随便你拖

div4:我可以随窗口滑动，把我拖到最下面，然后滚动网页看看

作者: Longbill
www.longbill.cn

参数说明:

drag(obj [,scroll]);

obj:对象的id或对象本身;

scroll(可选):对象是否随窗口拖动而滑动，默认为否

鼠标右键查看源代码

drag("div1");
drag("div2");
drag("div3");
drag("div4",1);
drag("div5",1);
drag("div6",1);

[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]