得到对象以及鼠标在页面的绝对位置(转)

获取页面元素的位置对我们很重要，如何获得元素位于页面的绝对位置呢？通过offsetLeft,offsetTop可以获得对象的左边距和上边距，但是不同浏览器因为对象处于的地位而会有些不同的解析，例如有些时候计算边距时没有把parent的边距计算进去，下面的函数将可以获得对象绝对的位置。

如下：
// get absolute Left position
//建立者:jiarry@hotmail.com
//返回对象位于窗口的绝对左边距离
function getAbsoluteLeft( ob ){
if(!ob){return null;}
var obj = ob;
var objLeft = obj .offsetLeft;
while( obj != null && obj .offsetParent != null && obj .offsetParent.tagName != "BODY" ){
objLeft += obj .offsetParent.offsetLeft;
obj = obj .offsetParent;
}
return objLeft ;
}

// get absolute TOP position
//建立者:jiarry@hotmail.com
//返回对象位于窗口的绝对上边距离
function getAbsoluteTop( ob ){
if(!ob){return null;}
var obj = ob;
var objTop = obj .offsetTop;
while( obj != null && obj .offsetParent != null && obj .offsetParent.tagName != "BODY" ){
objTop += obj .offsetParent.offsetTop;
obj = obj .offsetParent;
}
return objTop ;
}

获得页面的的宽高，左右边距有这些：
window.screen.width;
window.screen.height;
window.document.body.offsetWidth;
window.document.body.offsetHeight;
window.screen.availWidth;
window.screen.availHeight;
window.document.body.offsetWidth;
window.document.body.offsetHeight;
window.screen.availWidth;
window.screen.availHeight;
window.document.body.scrollWidth;
window.document.body.scrollHeight;
window.document.body.clientHeight;
window.document.body.clientWidth;

通过事件来获得鼠标位置主要有这些:
e.layerX;
e.layerY;
e.pageX;
e.pageY;
e.screenX;
e.screenY;
e.offsetX;
e.offsetY;
e.clientX;
e.clientY;

//获得对象相对于父级的位置
obj .offsetLeft;
obj .offsetTop;
obj .offsetWidth;
obj .offsetHeight;

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下面是各浏览器关于页面位置的全部属性,包括获得鼠标位于该位置的实时x,y坐标：getPosition.html
<body>
<div id="object" style="background-color:green;color:white" onmousemove="getPosition(this,event);" >object,请在此处移动鼠标</div>
<div id="showinfo"></div>
<script>

// get absolute Left position
//建立者:jiarry@hotmail.com
//返回对象位于窗口的绝对左边距离
function getAbsoluteLeft( ob ){
if(!ob){return null;}
var obj = ob;
var objLeft = obj .offsetLeft;
while( obj != null && obj .offsetParent != null && obj .offsetParent.tagName != "BODY" ){
objLeft += obj .offsetParent.offsetLeft;
obj = obj .offsetParent;
}
return objLeft ;
}

// get absolute TOP position
//建立者:jiarry@hotmail.com
//返回对象位于窗口的绝对上边距离
function getAbsoluteTop( ob ){
if(!ob){return null;}
var obj = ob;
var objTop = obj .offsetTop;
while( obj != null && obj .offsetParent != null && obj .offsetParent.tagName != "BODY" ){
objTop += obj .offsetParent.offsetTop;
obj = obj .offsetParent;
}
return objTop ;
}

var str="";
str+=" window.screen.width "+window.screen.width;
str+=" window.screen.height "+window.screen.height;
str+=" window.document.body.offsetWidth "+window.document.body.offsetWidth;
str+=" window.document.body.offsetHeight "+window.document.body.offsetHeight;
str+=" window.screen.availWidth "+window.screen.availWidth;
str+=" window.screen.availHeight "+window.screen.availHeight;
str+=" window.document.body.offsetWidth "+window.document.body.offsetWidth;
str+=" window.document.body.offsetHeight "+window.document.body.offsetHeight;
str+=" window.screen.availWidth "+window.screen.availWidth;
str+=" window.screen.availHeight "+window.screen.availHeight;
str+=" window.document.body.scrollWidth "+window.document.body.scrollWidth;
str+=" window.document.body.scrollHeight "+window.document.body.scrollHeight;
str+=" window.document.body.clientHeight "+window.document.body.clientHeight;
str+=" window.document.body.clientWidth "+window.document.body.clientWidth;

var str1="";
function getPosition(obj,e){
str1="";
//str1 += str;
str1+=" e.layerX "+e.layerX;
str1+=" e.layerY "+e.layerY;
str1+=" e.pageX "+e.pageX;
str1+=" e.pageY "+e.pageY;
str1+=" e.screenX "+e.screenX;
str1+=" e.screenY "+e.screenY;
str1+=" e.offsetX "+e.offsetX;
str1+=" e.offsetY "+e.offsetY;
str1+=" e.clientX "+e.clientX;
str1+=" e.clientY "+e.clientY;
//
str1+=" obj.offsetLeft "+ obj .offsetLeft;
str1+=" obj.offsetTop "+ obj .offsetTop;
str1+=" obj.offsetWidth "+ obj .offsetWidth;
str1+=" obj.offsetHeight "+ obj .offsetHeight;

str1+="<hr> 绝对左边距"+ getAbsoluteLeft(obj);
str1+="<hr> 绝对上边距"+ getAbsoluteTop(obj);
document.getElementById("showinfo").innerHTML = str1;

}

document.write( str );
//alert(str)
</script>