获取浏览器视口大小

 1 window.onload = function() {
 2     alert("width: " + getPageScale().pageWidth + ", height: " + getPageScale().pageHeight);
 3 };
 4 
 5 /**
 6  * 获取浏览器视口大小
 7  * @return {object} 宽，高
 8  */
 9 function getPageScale(){
10     var pageWidth = window.innerWidth,
11         pageHeight = window.innerHeight;
12 
13     if (typeof pageWidth !== "number") {
14         if (document.compatMode === "CSS1Compat") {
15             pageWidth = document.documentElement.clientWidth;
16             pageHeight = document.documentElement.clientHeight;
17         }else{
18             pageWidth = document.body.clientWidth;
19             pageHeight = document.body.clientHeight;
20         }
21     }
22 
23     return {pageWidth, pageHeight};
24 }