GreenRobot: EventBus's isRegistered() method not working as expected

[lalit3686]

I am using EventBus for receiving the events. I want to check if my Activity is already registered or not as I need to register only once through the whole lifetime of the application, but the issue is that wheneven I come to that Activity which is registered EventBus registers it again and due to that multiple events are getting fired.

Below is my code sample!

    public void registerEventBus(){
        if(EventBus.getDefault().isRegistered(this)){
            Log.e(TAG, "already registered event bus for "+TAG);
        }
        else{
            EventBus.getDefault().register(this);
            Log.e(TAG, "registering event bus for "+TAG);
        }
    }

Also, find the screenshot of logs, in which you can see that initially it gives me proper response but once I move to that Activity again it registers the subscriber again!

NOTE: Please don't suggest me to unregister as I want it to be registered always!

[william-ferguson-au]

Are you sure that this is the same each time?
Try changing your log to
Log.e(TAG, "already registered event bus for " + this);

If your MainActivity is being destroyed and recreated (eg due to rotation) then it will be a different instance each time.

Also, when/where are you registering?
When/where are you unregistering?

[lalit3686]

Instance is different everytime as I am destroying the Activity and creating it everytime and registering it but why I am getting mutliple logs though instance is different?

If Activity 1 is destroyed and and I open it again say Activity 2 then why it is sending me the event registered with Activity 1?

[william-ferguson-au]

Because if you never unregistered Activity1 then EVentBus still has a reference to it, so will still send it messages.

You should ALWAYS unregister your subscriber at the equivalent exit point.

[lalit3686]

ok, got it thanks for the brief explanation!

It would be good that you answer on StackOverflow as well to keep for future users - http://stackoverflow.com/questions/39589046/greenrobot-eventbuss-isregistered-method-not-working-as-expected