Calling a method in one fragment from another

Question

I\'ve been trying for a while already (as well, searching in here) for something to help me to refresh listView in my MainFragment, when a button is pressed in other fragmen

Answer 1

you should use interface for this. define an interface in OtherFragment class and implement that in your MainActivity and define a public method in your MainFragment for refreshing your ListView and call that method from your MainActivity. here is an example :

public Class OtherFragment extends Fragment implements OnClickListener {

private Communicator communicator;

   ...

public void setCommunicator(Communicator communicator) {
    this.communicator = communicator;
}

@Override
public void onClick(View v) {
   communicator.clicked();
}

   public interface Communicator {
      public void clicked();
   }
}

and in your MainActivity :

public class MainActivity extends Activity implements OtherFragment.Communicator {

   MainFragment mainFragment;

   @Override
   protected void onCreate(Bundle b) {
      ...
      OtherFragment otherFragment = new OtherFragment();
      otherFragment.setCommunicator(this);
      ...
   }

   ...

   @Override 
   public void clicked() {
     mainFragment.updateList();
   }
}

and in your MainFragment :

public class MainFragment extends Fragment {

    ...

    public void updateList() {
        // update list
    }
}

Answer 2

In MainFragment class you can do the following code:

private static MainFragment instance = null;

@Override  
public void onCreate(@Nullable Bundle savedInstanceState) {  
    super.onCreate(savedInstanceState);  
    instance = this;  
}

public static MainFragment getInstance() {  
    return instance;  
} 

And in SocialMedia class you can call the method as follows:

MainFragment.getInstance().otherList();   

Answer 3

FragmentManager fm = getFragmentManager(); 
MainFragment fragm = (MainFragment)fm.findFragmentById(R.id.main_fragment); 
fragm.otherList(); 

This code worked best for me. And seems quite easy

Answer 4

To call a method from another object (a Fragment is an object) you need to have the reference of that object. So if you want to call MainFragment#otherList() from a SocialMedia instance, SocialMedia needs a reference to MainFragment.

For example:

public class SocialMedia {

    private MainFragment mainFragment = null;

    public void setMainFragment(final MainFragment mainFragment) {
        this.mainFragment = mainFragment
    }
}

Then you can use this.mainFragment.otherList().

Answer 5

            // Calling Parent Fragment method from Child Fragment.
        // Child Fragment
        AppCompatActivity activity = (AppCompatActivity) view.getContext();
        FragmentManager fragmentManager = activity.getSupportFragmentManager();
        NavigateFragment navigateFragment = (NavigateFragment) fragmentManager.findFragmentById(R.id.fragment_place_dashboard);
        navigateFragment.sayHelloWorld();


        // -- Some method in Parent Fragment(NavigateFragment).
        public void sayHelloWorld(){
            Log.d(TAG, "Hello World.");
        }