CODEWITHSUNDEEP
androidandroid-fragmentsandroid-activityandroid-savedstate
Schwafa
Schwafa

Reputation: 167

Passing String from Activity back to running Fragment in Android

There are a few posts about similar problems but I just don't get the wright answers and I hope that anyone can help me.

Situation: I have a MainActivity that contains several Fragments. In one Fragment I start a CameraActivity with an intent. When the user has taken the picture, the CameraActivity gets closed with finish() and we return back to the previous Fragment.

Goal: I give the Picture a certain name and would like to pass this name from the CameraActivity to the Fragment.

Problem: Even though I call finish() in the CameraActivity and the screen returns back to the previous Fragment, the method onSaveInstanceState(Bundle outstate) is never called. Why is that?

Or how could I solve the problem otherwise?

Here is my code: 

public class CameraActivity extends Activity {
    // more code here

    String imageFileName;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // some methods here
        finish(); // finish the current Activity and get back to previous Fragment
    }

    // more code here

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        Log.d(TAG_LOG, "onSaveInstanceState() called"); // is never called!
        outState.putString("imageFileName", imageFileName);
        super.onSaveInstanceState(outState);
    }
}

And in the Fragment I do this:

public class MapFragment extends Fragment implements View.OnClickListener {

    // more code here

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_map, container, false);
        // some methods here

        if (savedInstanceState != null) {
            String imageFileName = getArguments().getString("imageFileName");
            Log.d(TAG_LOG, "image filename: " + imageFileName);
        }

        return view;
    }

    // more code here
}

Any help is highly appreciated!

Upvotes: 2

Views: 955

Answers (2)

Gueg
Gueg

Reputation: 127

You should take a look at startActivityForResults. Here is a short example (haven't tried it but you will get the idea) :

Fragment

Intent intent = new Intent(MainActivity.this,CameraActivity.class);
getActivity().startActivityForResult(intent,RESULT_PIC_TAKEN); // you may start an activity from another activity, not a fragment

CameraActivity

Intent results = new Intent();
results.putExtra("com;yourpackage.PIC_NAME", picName);
setResult(CameraActivity.RESULT_OK,results);
finish();

Back to MainActivity (since you called getActivity())

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    if (requestCode == RESULT_PIC_TAKEN) {
        if(resultCode == Activity.RESULT_OK){
            Bundle results = data.getExtras();
            String picName = results.getString("com.yourpackage.PIC_NAME");
            // code, and send what you want to the fragment
        }
    }
}

Hope this will help you!

Upvotes: 1

MWU
MWU

Reputation: 9

Start the CameraActivity using startActivityForResult(), once you get the string to pass back in your previous screen, just create an Intent that will contain that string, and in your MainActivity, implement:

protected void onActivityResult(int requestCode, int resultCode, Intent data)

Get the string from the intent, and pass it to your fragment.

onSaveInstanceState is used for other purposes.

Upvotes: 0

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