eventbus指定接收者

http://greenrobot.org/eventbus/documentation/priorities-and-event-cancellation/

思路：设置订阅者的优先级，优先级高的接收事件处理，取消事件，事件无法继续往下传递，达到指定接收者的目的。

1.Subscriber Priorities

You may change the order of event delivery by providing a priority to the subscriber during registration.

@Subscribe(priority = 1); //设置优先级
public void onEvent(MessageEvent event) {
…
}
Within the same delivery thread (ThreadMode), higher priority subscribers will receive events before others with a lower priority. 

2.Cancelling event delivery

You may cancel the event delivery process by calling cancelEventDelivery(Object event) from a subscriber’s event handling method. Any further event delivery will be cancelled: subsequent subscribers won’t receive the event.

// Called in the same thread (default)
@Subscribe
public void onEvent(MessageEvent event){
// Process the event
…

EventBus.getDefault().cancelEventDelivery(event) ;  //取消事件传递
}
Events are usually cancelled by higher priority subscribers. Cancelling is restricted to event handling methods running in posting thread ThreadMode.PostThread.