getEvent<T> static method
获取监听
Implementation
static EventObservable<T> getEvent<T>(String event) {
var eventObservable = _eventMap[event];
if (eventObservable == null) {
eventObservable = _EventObservable<T>();
_eventMap[event] = eventObservable;
}
return eventObservable as EventObservable<T>;
}