CODEWITHSUNDEEP
androidandroid-intent
Fox
Fox

Reputation: 463

android get intent in a running activity

I have two activities A and B and the activity A starts B and keeps running. I want to send back some info from B to A which is still running in background.

I'm doing this but B is starting a new A activity instead of using the previous one.

B

Intent intent = new Intent();
intent.setClass(context, ObtenerDatos.class);
intent.putExtra("EXTRA_ID", StationID);
context.startActivity(intent);
finish();

And A gets the data as this:

@Override
    public void onResume() {
      super.onResume();
      Bundle extras = getIntent().getExtras();
      if (extras != null) {
           String datas= extras.getString("EXTRA_ID");
           if (datas!= null) {
                // do stuff
           }
      }
    }

What am I doing wrong?

Thanks!

Upvotes: 0

Views: 936

Answers (4)

evaristokbza
evaristokbza

Reputation: 872

What about using startActivityForResult() from A to start B?

When B is done, just set the result and call finish() 

Intent intent = new Intent();
intent.putExtra(DATA_EXTRA, data);
setResult(Activity.RESULT_OK, intent);

finish();

Then, in A you use onActivityResult()

Upvotes: 0

Stefano
Stefano

Reputation: 3215

Intent intent = new Intent();
intent.putExtra("EXTRA_ID", StationID);
context.startActivity(intent);
finish();

I think that the problem is the finish(); becouse how can Acvtivity B still run if you finish it?

Upvotes: -1

Bryan Herbst
Bryan Herbst

Reputation: 67189

Typically you use startActivityForResult() and onActivityResult() for this (see Starting Activities and Getting Results).

For example, in Activity A:

private static final int B_REQUEST = 0;

// ...

public void onClick(View v) {
    Intent bIntent = new Intent(this, ActivityB.class);
    startActivityForResult(bIntent, B_REQUEST);
}

public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == B_REQUEST && resultCode == Activity.RESULT_OK) {
        // Get data out of the data Intent
    }
}

In ActivityB when you want to return to Activity A:

Intent data = new Intent();
// use intent.putExtra() to store your result data
setResult(Activity.Result_OK, data);
finish();

Upvotes: 1

makovkastar
makovkastar

Reputation: 5020

You can use flag Intent.FLAG_ACTIVITY_NEW_TASK. If an activity is already running it will be brought to the front of the screen with the state it was last in instead of creating a new one.

Intent intent = new Intent();
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.setClass(context, ObtenerDatos.class);
intent.putExtra("EXTRA_ID", StationID);
context.startActivity(intent);
finish();

Upvotes: 1

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