GreenRobot EventBus not receiving message in Background service posted by Activity

Question

In my Activity I send EventBus

@Override
protected void onResume() {
        super.onResume();
        EventBus.getDefault().post(new String("We are the champions"));
}

In my background service I register EventBus and try to get sent message from Activity like this

@Override
public void onCreate() {
    super.onCreate();
    EventBus.getDefault().register(this);
}

@Override
public void onDestroy() {
   super.onDestroy();
   EventBus.getDefault().unregister(this);
}

public void onEventBackgroundThread(String s){
        Log.d(TAG, "onEventBackgroundThread: " + s);
    }

But nothing happens. I tried to search internet but couldn't get answer.

Errors I get

No subscribers registered for event class java.lang.String
No subscribers registered for event class de.greenrobot.event.NoSubscriberEvent

1.Edit

I already have EventBus communication from Service to Activity. But now I want to have it also to work in reverse direction(From Activity to Service). So is it possible that it conflicts?

It actually works in both directions when I start service with startService(Intent); in one of app Activities. But if I try to use new thread for background service it can't make communication. — Rafael, Jun 08 '15 at 05:03
Yes, I eventually got it to work by using `startService`. Thanks for your response. — iRuth, Jun 08 '15 at 07:03
I'm not sure I understand what you mean by "thread in background service", but I started threads in the background service that I created and I was able to accomplish my task using the `EventBus`. — iRuth, Jun 08 '15 at 07:08
I tried to search my old code, but couldn't find the reason I couldn't communicate with background service. But as far as I remember it was something related to threads. — Rafael, Jun 08 '15 at 09:18
Answer for background service is mentioned [here][1] [1]: http://stackoverflow.com/questions/15431768/how-to-send-event-from-service-to-activity-with-otto-event-bus — M.Hefny, Jul 25 '15 at 21:12

score 2 · Answer 1 · edited Mar 19 '15 at 20:41

First you need to define a custom message event class:

public class MyMessageEvent {
   String s;
}

Then you should add a subscriber method into your service. Key thing is to include your MyMessageEvent as the parameter:

public void onEventBackgroundThread(MyMeasageEvent  myEvent){
        Log.d(TAG, "onEventBackgroundThread: " + myEvent.s);
    }

Plus make sure your service registers with EventBus.

Finally, create a MyMessageEvent in your activity and post it on the eventbus:

MyMessageEvent myEvent = new MyMessageEvent() ;
myEvent.s = "hello" ;

EventBus.getDefault().post(myEvent) ;

If it still doesn't get received, try splitting the post onto a seperate line from the get default. Sometimes chaining doesn't work.

you saved me, it just just the chaining...thanks a lot – Ale Mar 08 '18 at 17:11 — Ale, Mar 08 '18 at 17:11

score 0 · Answer 2 · answered Dec 16 '14 at 05:14

0

I have not used greenrobot before but I think it should be similar to guava's eventbus. I think you should create an event class instead of using String. You can have a look at https://github.com/greenrobot/EventBus. e.g.

public class MessageEvent {
String s;
}

answered Dec 16 '14 at 05:14

vincentzhou

710
6
18

I tried your solution, but still receive similar error – Rafael Dec 16 '14 at 07:53

GreenRobot EventBus not receiving message in Background service posted by Activity

2 Answers2