Send data from activity to fragment in Android

Question

I have two classes. First is activity, second is a fragment where I have some EditText. In activity I have a subclass with async-task and in method doInBa

Answer 1

If an activity needs to make a fragment perform an action after initialization, the easiest way is by having the activity invoke a method on the fragment instance. In the fragment, add a method:

public class DemoFragment extends Fragment {
  public void doSomething(String param) {
      // do something in fragment
  }
}

and then in the activity, get access to the fragment using the fragment manager and call the method:

public class MainActivity extends FragmentActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        DemoFragment fragmentDemo = (DemoFragment) 
            getSupportFragmentManager().findFragmentById(R.id.fragmentDemo);
        fragmentDemo.doSomething("some param");
    }
}

and then the activity can communicate directly with the fragment by invoking this method.