弹出DIV层 完美 居中js

showDiv($("#ShowDiv"));

function showDiv(obj){
 $(obj).show();
 center(obj);
 $(window).scroll(function(){
  center(obj);
 });
 $(window).resize(function(){
  center(obj);
 }); 
}
function center(obj){
 var windowWidth = document.documentElement.clientWidth;  
 var windowHeight = document.documentElement.clientHeight;  
 var popupHeight = $(obj).height();  
 var popupWidth = $(obj).width();   
 $(obj).css({  
  "position": "absolute",  
  "top": (windowHeight-popupHeight)/2+$(document).scrollTop(),  
  "left": (windowWidth-popupWidth)/2  
 }); 
}

 

另外div的css 必须包含：

position: absolute;

 

 

然后附上禁用滚动条：

 

var temp_h1 = document.body.clientHeight;
var temp_h2 = document.documentElement.clientHeight;
var isXhtml = (temp_h2<=temp_h1&&temp_h2!=0)?true:false;
var htmlbody = isXhtml?document.documentElement:document.body;

 

 

 

htmlbody.style.overflow = "auto";   //启用

 

htmlbody.style.overflow = "hidden";  //禁用

 

 然后一切ok

 

 

 

据说看了不回帖的人，经常玩 DeBug