Sending Data To The Container Activity

I have this issue of sending some data back and forth between a fragment and its container activity, I succeeded in doing it. What puzzles me is sending my data from the fragment t

Solution 1:

The Right approach is to use Interfaces. Don't use onStop or setRetainInstance()

See this. It will solve you problem. Pass data from fragment to actvity

Solution 2:

You can also achieve this by using Interface, using an EventBus like LocalBroadcastManager, or starting a new Activity with an Intent and some form of flag passed into its extras Bundle or something else.

Here is an example about using Interface:

1. Add function sendDataToActivity() into the interface (EventListener).

//EventListener.javapublicinterfaceEventListener {

    publicvoidsendDataToActivity(String data);
}

2. Implement this functions in your MainActivity.

// MainActivity.javapublicclassMainActivityextendsAppCompatActivityimplementsEventListener {

    @OverrideprotectedvoidonCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @OverridepublicvoidsendDataToActivity(String data) {
        Log.i("MainActivity", "sendDataToActivity: " + data);
    }
}

3. Create the listener in MyFragment and attach it to the Activity.

4. Finally, call function using listener.sendDataToActivity("Hello World!").

// MyFragment.java publicclassMyFragmentextendsFragment {

    privateEventListener listener;

    @OverridepublicvoidonAttach(Activity activity)
    {
        super.onAttach(activity);
        if(activity instanceofEventListener) {
            listener = (EventListener)activity;
        } else {
            // Throw an error!
        }
    }

    @OverridepublicViewonCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_my, container, false);

        // Send data
        listener.sendDataToActivity("Hello World!");

        return view;
    }

    @OverridepublicvoidonDetach() {
        super.onDetach();

        listener = null;
    }
}

Hope this will help~