event

1. 事件对象的获取

var event = event || window.event; // 兼容写法, ie678中支持window.event

2. event事件重要内容

event.png

3. screenX、pageX、clientX的区别：

qubie.png

3. 获取屏幕可视区域的宽高

 function client(){
        if(window.innerHeight !== undefined){
            return {
                "width": window.innerWidth,
                "height": window.innerHeight
            }
        }else if(document.compatMode === "CSS1Compat"){
            return {
                "width": document.documentElement.clientWidth,
                "height": document.documentElement.clientHeight
            }
        }else{
            return {
                "width": document.body.clientWidth,
                "height": document.body.clientHeight
            }
        }
    }

// 阻止冒泡
  event = event || window.event;

  if(event && event.stopPropagation){
         event.stopPropagation();
   }else{
        event.cancelBubble = true; // IE10以下
   }

// 获取目标元素的兼容写法:
var obj = event.target ? event.target : event.srcElement;