javascript处理事件的一些兼容写法

绑定事件

01. var addEvent = function( obj, type, fn ) {
02.     if (obj.addEventListener)
03.         obj.addEventListener( type, fn, false );
04.     else if (obj.attachEvent) {
05.         obj["e"+type+fn] = fn;
06.         obj.attachEvent( "on"+type, function() {
07.             obj["e"+type+fn]();
08.         } );
09.     }
10. };

另一个实现

01. var addEvent = (function () {
02.     if (document.addEventListener) {
03.         return function (el, type, fn) {
04.             el.addEventListener(type, fn, false);
05.         };
06.     } else {
07.         return function (el, type, fn) {
08.             el.attachEvent('on' + type, function () {
09.                 return fn.call(el, window.event);
10.             });
11.         }
12.     }
13. })();

移除事件

1. var removeEvent = function(obj, type, fn) {
2.     if (obj.removeEventListener)
3.         obj.removeEventListener( type, fn, false );
4.     else if (obj.detachEvent) {
5.         obj.detachEvent( "on"+type, obj["e"+type+fn] );
6.         obj["e"+type+fn] = null;
7.     }
8. }

加载事件与脚本

01. var loadEvent = function(func) {
02.     var oldonload = window.onload;
03.     if (typeof window.onload != 'function') {
04.         window.onload = func;
05.     }else {
06.         window.onload = function() {
07.             oldonload();
08.             func();
09.         }
10.     }
11. }

阻止事件

01. var cancelEvent = function(event) {
02.     event = event||window.event
03.     if (event.preventDefault) {
04.         event.preventDefault(  );
05.         event.stopPropagation(  );
06.     } else {
07.         event.returnValue = false;
08.         event.cancelBubble = true;
09.     }
10. }

取得事件源对象

相当于Prototype.js框架的Event.element(e)

1. var getTarget = function(event){
2.     event = event || window.event;
3.     var obj = event.srcElement ? event.srcElement : event.target;
4.     return obj