根据我的实验,这引用了event.currentTarget对象.
这种行为是否在标准的某处提到过？
根据“JavaScript The Definitive Guide”一书,这指的是似乎错误的事件目标. event.currentTarget似乎更合乎逻辑,因为事件处理程序被调用为HTML元素对象的方法.
有人可以澄清一下吗？
In case of bubbling I see “this” changes and means the
event.currentTarget.
解决方法
我在HTML5 event handler processing algorithm中找到了一个参考：
Invoke
callbackwith one argument,the value of which is the Event objectE,with the callback this value set toE‘scurrentTarget.
DOM 3级事件规范在以前的版本中没有说太多 – 它本来是语言无关的. Appendix F: ECMAScript Language Binding刚才说明了
EventListener function:
This function has no return value. The parameter shall be an object that implements theEventinterface.
但是,当前版本省略了这些绑定.在其词汇表附录event listeners中描述：
event handler,event listener: An object that implements the
EventListenerinterface and provides anEventListener.handleEvent()callback method. Event handlers are language-specific. Event handlers are invoked in the context of a particular object (the 07003) and are provided with theeventobject itself.
此外,即将推出的DOM Level 4草案,其goals包含将DOM与EcmaScript的需求对齐,确实明确说明了in the Dispatching Events section：
If
listener‘s callback is a Function object,its 07006 is theevent‘s 07007 attribute value.
