js添加事件、移除事件、阻止冒泡、阻止浏览器默认行为等写法(兼容IE/FF/CHROME)


添加事件

var addEvent = function( obj, type, fn ) {
if (obj.addEventListener)
obj.addEventListener( type, fn, false );
else if (obj.attachEvent) {
obj["e"+type+fn] = fn;
obj.attachEvent( "on"+type, function() {
obj["e"+type+fn].call(obj, window.event);
} );
}
};

移除事件

var removeEvent = function( obj, type, fn ) {
if (obj.removeEventListener)
obj.removeEventListener( type, fn, false );
else if (obj.detachEvent) {
obj.detachEvent(  "on" +type, obj["e"+type+fn] );
obj["e"+type+fn] = null;
}
};

阻止事件(包括冒泡和默认行为)

var stopEvent = function(e){
e = e || window.event;
if(e.preventDefault) {
e.preventDefault();
e.stopPropagation();
}else{
e.returnValue = false;
e.cancelBubble = true;
}
},

仅阻止事件冒泡

var stopPropagation = function(e) {
e = e || window.event;
if (!+"\v1″) {
e.cancelBubble = true;
} else {
e.stopPropagation();
}
}

仅阻止浏览器默认行为

var  preventDefault  = function(e) {
e = e || window.event;
if(e.preventDefault) {
e.preventDefault();
}else{
e.returnValue = false;
}
}

取得事件源对象

var getEventTarget = function(e){
e = e || window.event;
var target = event.srcElement ? event.srcElement : event.target;
return target;
}

附：绑定onpropertychange事件

onpropertychange，它在一个元素的属性发生变化的时候触发，一般用在表单元素中捕获其value值改变，它比onchange事件更实时捕获它的改变，不过为微软私有事件。FF大致和它相似的有oninput事件，不过它只针对textfield与textarea的value属性。safari，firefox，chrome与
opera都支持此事件。

var addPropertyChangeEvent = function (obj,fn) {
if(window.ActiveXObject){
obj.onpropertychange = fn;
}else{
obj.addEventListener("input",fn,false);
}
}