<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
#div1{ 100px; height: 100px; background-color: #4D4D4D; position: absolute; cursor: pointer; -webkit-box-shadow: 3px 3px 0px 3px #C7C7C7; box-shadow: 3px 3px 3px 0px #C7C7C7; }
#parent{ 500px; height: 500px; border: 1px solid #CDCDCD; position: relative; margin: 0 auto; background-color: #F4F4F4; }
</style>
</head>
<body>
<div id="parent">
<div id="div1"></div>
</div>
<script type="text/javascript">
window.onload = function (){
var oDiv = document.getElementById('div1');
var oParent = document.getElementById('parent');
var sent = {
l : 0,
r : oParent.offsetWidth - oDiv.offsetWidth,
t : 0,
b : oParent.offsetHeight - oDiv.offsetHeight,
n : 10
}
drag(oDiv,sent);
}
function drag(obj,sent){
var dmW = document.documentElement.clientWidth || document.body.clientWidth;
var dmH = document.documentElement.clientHeight || document.body.clientHeight;
var sent = sent || {};
var l = sent.l || 0;
var r = sent.r || dmW - obj.offsetWidth;
var t = sent.t || 0;
var b = sent.b || dmH - obj.offsetHeight;
var n = sent.n || 10;
obj.onmousedown = function (ev){
var oEvent = ev || event;
var sentX = oEvent.clientX - obj.offsetLeft;
var sentY = oEvent.clientY - obj.offsetTop;
document.onmousemove = function (ev){
var oEvent = ev || event;
var slideLeft = oEvent.clientX - sentX;
var slideTop = oEvent.clientY - sentY;
if(slideLeft <= l){
slideLeft = l;
}
if(slideLeft >= r){
slideLeft = r;
}
if(slideTop <= t){
slideTop = t;
}
if(slideTop >= b){
slideTop = b;
}
obj.style.left = slideLeft + 'px';
obj.style.top = slideTop + 'px';
}
document.onmouseup = function (){
document.onmousemove = null;
document.onmouseup = null;
}
return false;
}
}
</script>
</body>
</html>