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Start your free trialvenkateshgangietti
6,226 Pointsin implemeting interface methods there is no syntax error
I put everything right
public class NewsFragment extends Fragment {
public interface NewsListener{
public void onNewsItemSelected(int index);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_news, container, false);
return view;
}
}
public class MainActivity extends AppCompatActivity implements NewsListener {
public void onNewsItemSelected(int index){
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
NewsFragment newsFragment = new NewsFragment();
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.placeholder, newsFragment);
fragmentTransaction.commit();
}
}
2 Answers
Seth Kroger
56,413 PointsThe NewsListener interface is inside NewsFragment, making it an inner interface. Whenever you have an inner class or interface you need to refer to it as OuterClass.InnerClass. So your first line of MainActivity should be:
public class MainActivity extends AppCompatActivity implements NewsFragment.NewsListener {
Alexander Davison
65,469 PointsI'm no Android developer, sadly, but I do notice something that might be causing a Syntax error (I do know some Java). Check this out:
public void onNewsItemSelected(int index); //<-------- Sadly this is invalid Java code
public void onNewsItemSelected(int index) {} //<-------- This successfully creates a function with no body. Yay!
I hope this helps
~Alex
Seth Kroger
56,413 PointsAlex, when you're declaring (as opposed to implementing) an interface in Java the first line is valid because you are just declaring an empty method signature.