Send Data to Fragment from Activity with EventBus

Question

I looked at all the questions and answers about this. But I could not find the answers to my question.

I have the Fragment : MyFragment . In it button and textView . I want to that When I will click on the button it will open MyActivity with two buttons: cancelButton and saveButton . When I will click cancelButton or saveButton finishes this Activity and textView in MyFragment will change to that what I send in MyActivity , for example "Cancel Clicked" or "Save Clicked".

What I did:

In MyFragment :

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

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

@Subscribe
public void onSaveEvent(Message message) {
    textView.setText(message.getMessage());
};

@Subscribe
public void onCancelEvent(Message message) {
    textView.setText(message.getMessage());
};

In MyActivity :

@OnClick(R.id.saveBtn)
public void saveClick(){
    finish();
    EventBus.getDefault().postSticky(new Message("Save clicked!"));
}

@OnClick(R.id.cancelBtn)
public void cancelClick(){
    finish();
    EventBus.getDefault().postSticky(new Message("Cancel Clicked"));
}

But it does not work I think it because when I start MyActivity , Event Bus unregisters in onPause() therefor can`t receive event

I tried with interfaces and it worked. But I want to realize it with EventBus

How can I do on Event Bus ?

Answer 1

You can solve this with a StickyEvents .

In Fragment

@Subscribe(sticky = true, threadMode = ThreadMode.MAIN)
public void onEvent(Message message) {
    Message stickyEvent = EventBus.getDefault().getStickyEvent(Message.class);
    if(stickyEvent != null) {
        tv.setText(message.getMessage());
        EventBus.getDefault().removeStickyEvent(stickyEvent);
    }
};

Answer 2

1. According to this , you should register and unregister in onStart and onStop.

2. I think you should post events before calling finish() in your activity.