javascript --- 兼容的那些事

绑定事件

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]();
        } );
    }
};

另一个实现：

var addEvent = (function () {
    if (document.addEventListener) {
        return function (el, type, fn) {
            el.addEventListener(type, fn, false);
        };
    } else {
        return function (el, type, fn) {
            el.attachEvent('on' + type, function () {
                return fn.call(el, window.event);
            });
        }
    }
})();

绑定onpropertychange事件

onpropertychange是微软制造的一个事件，它在一个元素的属性发生变化的时候触发，常见的有文本的长度改变，样长改变等，FF大致和它相似的属性为oninput事件，不过它只针对textfield与textarea的value属性。safari，firefox，chrome与opera都支持此属性。

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

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;
    }
};

加载事件 (如果把该函数调用放到window.onoad中，就没有效果了)

var loadEvent = function(fn) {
    var oldonload = window.onload;
    if (typeof window.onload != 'function') {
        window.onload = fn;
    }else {
        window.onload = function() {
            oldonload();
            fn();
        }
    }
}

阻止默认事件

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

<form action="">
    <input type="text" value="请输入您的手机号">
    <input type="submit" id="sub" value="提交">
</form>
var sub = document.getElementById('sub');
sub.onclick = function(){
    stopEvent();
}

如果仅仅是阻止事件冒泡

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

取得事件源对象

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

function getEvent() {
    if (window.event) return window.event;
    var c = getEvent.caller;
    while (c.caller) c = c.caller;
    return c.arguments[0];
} 

var getEvent = function(e) {
  var e = e || window.event;
  if (!e) {
    var c = this.getEvent.caller;
    while (c) {
      e = c.arguments[0];
      if (e && (Event == e.constructor || MouseEvent  == e.constructor)) {
        break;
      }
      c = c.caller;
    }
  }
  var target = e.srcElement ? e.srcElement : e.target,
  currentN = target.nodeName.toLowerCase(),
  parentN  = target.parentNode.nodeName.toLowerCase(),
  grandN = target.parentNode.parentNode.nodeName.toLowerCase();
  return [e,target,currentN,parentN,grandN];
}