CODEWITHSUNDEEP
androidandroid-fragments
MeknessiHamida
MeknessiHamida

Reputation: 185

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 to the activity, at first I implemented OnResume(), OnStop() and sent the data through an intent and that created an infinite loop so I removed them. Then I did setRetainInstance(true) and it worked and gave me the wanted behavior.

My Question is How my data are really being sent and where in the fragment lifecycle ?

Upvotes: 1

Views: 114

Answers (2)

Ferdous Ahamed
Ferdous Ahamed

Reputation: 21756

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.java

public interface EventListener {

    public void sendDataToActivity(String data);
}

2. Implement this functions in your MainActivity.

// MainActivity.java

public class MainActivity extends AppCompatActivity implements EventListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public void sendDataToActivity(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 

public class MyFragment extends Fragment {

    private EventListener listener;

    @Override
    public void onAttach(Activity activity)
    {
        super.onAttach(activity);
        if(activity instanceof EventListener) {
            listener = (EventListener)activity;
        } else {
            // Throw an error!
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

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

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

        return view;
    }

    @Override
    public void onDetach() {
        super.onDetach();

        listener = null;
    }
}

Hope this will help~

Upvotes: 1

Ishaan Kumar
Ishaan Kumar

Reputation: 985

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

Upvotes: 1

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