17.3 Event Handler Invocation
Once you’ve registered an event handler, the web browser will invoke it automatically when an event of the specified type occurs on the specified object. This section describes event handler invocation in detail, explaining event handler arguments, the invocation context (the this value), the invocation scope, and the meaning of the return value of an event handler. Unfortunately, some of these details are different for IE8 and before than for other browsers.
In addition to describing how individual handlers are invoked, this section also explains how events propagate: how a single event can trigger the invocation of multiple handlers on the original event target and also on containing elements of the document.欢迎转载,转载请注明来自一手册:http://yishouce.com/book/1/27735.html