JavaScript事件

 1 var EventUtil = {
 2     addHandler: function(element,type,handler) {
 3         if(element.addEventListener) {
 4             element.addEventListener(type,handler,false);
 5         }else if(element.attachEvent) {
 6             element.attachEvent("on"+type,handler);
 7         }else {
 8             element["on" +type] = handler;
 9         }
10     },
11     removeHandler: function(element,type,handler){
12         if(element.removeEventListener) {
13             element.removeEventListener(type,handler,false);
14         }else if(element.detachEvent) {
15             element.detachEvent("on"+type,handler);
16         }else {
17             element["on" +type] = null;
18         }
19     },
20     getEvent: function(event) {
21         return event ? event : window.event;
22     },
23     getTarget: function(event) {
24         return event.target || event.srcElement;
25     },
26     preventDefault: function(event){
27         if(event.preventDefault) {
28             event.preventDefault();
29         }else {
30             event.returnValue = false;
31         }
32     },
33     stopPropagation: function(event) {
34         if(event.stopPropagation) {
35             event.stopPropagation();
36         }else {
37             event.cancelBubble = true;
38         }
39     },
40     getRelatedTarget: function(event){
41         if (event.relatedTarget){
42             return event.relatedTarget;
43         } else if (event.toElement){
44             return event.toElement;
45         } else if (event.fromElement){
46             return event.fromElement;
47         } else {
48             return null;
49         }
50     },
51     getWheelDelta: function(event) {
52         if(event.wheelDelta) {
53             return event.wheelDelta;
54         }else {
55             return -event.detail * 40
56         }
57     },
58     getCharCode: function(event) {
59         if(typeof event.charCode == ‘number‘) {
60             return event.charCode;
61         }else {
62             return event.keyCode;
63         }
64     }
65 };