Android Refresh A Fragment List From Its Parent Activity

Answer :

You can easily achieve this using INTERFACE

MainActivity.java

public class MainActivity extends Activity {      public FragmentRefreshListener getFragmentRefreshListener() {         return fragmentRefreshListener;     }      public void setFragmentRefreshListener(FragmentRefreshListener fragmentRefreshListener) {         this.fragmentRefreshListener = fragmentRefreshListener;     }      private FragmentRefreshListener fragmentRefreshListener;      @Override     public void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);           Button b = (Button)findViewById(R.id.btnRefreshFragment);          b.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View view) {                 if(getFragmentRefreshListener()!=null){                     getFragmentRefreshListener().onRefresh();                 }             }         });       }       public interface FragmentRefreshListener{         void onRefresh();     }  } 

MyFragment.java

public class MyFragment extends Fragment {      @Override     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {         View v = null; // some view          /// Your Code           ((MainActivity)getActivity()).setFragmentRefreshListener(new MainActivity.FragmentRefreshListener() {             @Override             public void onRefresh() {                  // Refresh Your Fragment             }         });           return v;     } } 

• Just make your update/refresh method public and call it from your Activity.

OR

• Use LocalBroadcastManager or EventBus to send event from your Activity, and by subscribing to this event in a Fragment - react to it and call refresh/update method.

Your activity can call methods in the fragment by acquiring a reference to the Fragment.

(1) Provide a tag when you add your fragment.

transaction.add(R.id.fragment_container, myFragment, "myfragmentTag"); 

(2) In your hosting activity you can find the fragment and have access to it's methods.

FragmentManager fm = getSupportFragmentManager(); myFragment f = (myFragment) fm.findFragmentByTag("myfragmentTag"); f.refreshAdapter() 

(3) refreshAdapter() could now call adapter.notifyDataSetChanged().

This is one of the recommended ways to communicate up to a fragment. The interface implementation is mainly for communicating back to the activity.