EventBus is not triggered in fragments android

Question

What Am I doing:

I have a subscriber in MainActivity.Java

I have registered in OnStart of activity

@Override
    public void onCreate() {
        super.onCreate();
        //Register the event bus for the screen
        EventBus.getDefault().register(this);

    }


@Subscribe(threadMode = ThreadMode.MAIN)
public void onMessageEvent(BusCategories event) {
        //On Click of Categories Label

}

---

Then, I have a Publisher in the FragmentA which is

EventBus.getDefault().post(new BusCategories(mUploadProducts.getCategories()));

---

So a event in Fragment is triggered calls in main activity

1. This Is working, but say I go to power save mode in phone where onPause is triggered and come back again the subscriber never gets triggered
2. How to properly handle this

Answer 1

You should handle registering and unregistering in onStart and onStopmethods or onResume and onPause methods respectively.

Answer 2

In my case, you need to make the event nullable object if you are using Kotlin. for example :

//this will not tigger by eventbus  
@Subscribe
fun onEvent(message Short){

}


//but will trigger by event bus  
@Subscribe
fun onEvent(message Short?){

}