其实就一句话: Each event can have multiple listeners, but a listener can't listen to more than a single event. If you want a class listening to many events, you should use the Event Subscribers. 每个事件均可有多个监听器,但是一个监听器只能监听一个事件。如果想在一个类中监听多个事件,就需要适用事件订阅者。