1 // 把所有方法封装到一个对象里面，充分考虑兼容写法 2 var EventUtil = { 3   // 添加DOM事件 4   addEvent: function(element, type, handler) { 5     if(element.addEventListener) { //DOM2级 6       element.addEventListener(type, handler, false); 7     }else if(element.attachEvent) {  //IE 8       element.attachEvent("on"+ type, handler); 9     }else {10       element["on" + type] = handler;11     }12   },13   // 移除DOM事件14   removeEvent: function(element, type, handler) {15     if(element.removeEventListener) { //DOM2级16       element.removeEventListener(type, handler, false);17     }else if(element.detachEvent) {  //IE18       element.detachEvent("on"+ type, handler);19     }else {20       element["on" + type] = null;21     }22   },23   // 阻止事件冒泡24   stopPropagation: function(ev) {25     if(ev.stopPropagation) {26       ev.stopPropagation();27     }else {28       ev.cancelBubble = true;29     }30   },31   // 阻止默认事件32   preventDefault: function(ev) {33     if(ev.preventDefault) {34       ev.preventDefaule();35     }else {36       ev.returnValue = false;37     }38   },39   // 获取事件源对象40   getTarget: function(ev) {41     return event.target || event.srcElement;42   },43   // 获取事件对象44   getEvent: function(e) {45     var ev = e || window.event;46     if(!ev) {47       var c = this.getEvent.caller;48       while(c) {49         ev = c.arguments[0];50         if(ev && Event == ev.constructor) {51           break;52         }53         c = c.caller;54       }55     }56     return ev;57   }58 };59