Fragment not attached to a context

Question

In activity in Toolbar I got a button which need to call method from fragment and update list in that fragment. Now it is an error. Calling in activity

@Override public boolean onOptionsItemSelected(MenuItem item) {     switch (item.getItemId()){         case  R.id.menu_sort:             ListFragment listFragment = new ListFragment();             listFragment.sortByPopularity();             break;     }     return super.onOptionsItemSelected(item); } 

Fragment code. I have found an error when Activity not attached. But nothing with context

public class ListFragment extends Fragment implements ListAdapter.ItemClickListener {      /**      * Needed      */     RecyclerView recyclerView;     View view;     List<BasePojo.Result> list;     ListAdapter listAdapter;      public ListFragment() {     }      @Override     public View onCreateView(LayoutInflater inflater, ViewGroup container,                              Bundle savedInstanceState) {          /**          * Main Initialization          */         view = inflater.inflate(R.layout.fragment_list, container, false);         recyclerView = view.findViewById(R.id.recycler_list_detailed);         recyclerView.setLayoutManager(new GridLayoutManager(getActivity(), 2));         list = new ArrayList<>();         listAdapter = new ListAdapter(list, setOnItemClickCallback());         recyclerView.setAdapter(listAdapter);          RetrofitClient.getApiService().getPhotosList(getString(R.string.api_key)).enqueue(new Callback<BasePojo>() {             @Override             public void onResponse(Call<BasePojo> call, Response<BasePojo> response) {                 BasePojo basePojo = response.body();                 list.addAll(basePojo.getResults());                 recyclerView.getAdapter().notifyDataSetChanged();             }              @Override             public void onFailure(Call<BasePojo> call, Throwable t) {                 Log.d("tag", "Response failed" + t.toString());              }         });           return view;     }      @Override     public void onItemClick(View view, int position) {         Log.v("in on click", "value " + position);      }      private OnItemClickListener.OnItemClickCallback setOnItemClickCallback() {         OnItemClickListener.OnItemClickCallback onItemClickCallback = new OnItemClickListener.OnItemClickCallback() {             @Override             public void onItemClicked(View view, int position) {                 BasePojo.Result itemClicked = list.get(position);                 Bundle bundle = new Bundle();                 bundle.putString("title", itemClicked.getOriginalTitle());                 bundle.putString("overview", itemClicked.getOverview());                 bundle.putString("release_date", itemClicked.getReleaseDate());                 bundle.putString("vote_average", itemClicked.getVoteAverage().toString());                 bundle.putString("poster_path", itemClicked.getPosterPath());                 DetailedFragment detailedFragment = new DetailedFragment();                 detailedFragment.setArguments(bundle);                 FragmentManager manager = getActivity().getSupportFragmentManager();                 FragmentTransaction transaction = manager.beginTransaction();                 transaction.replace(R.id.main_frame_list, detailedFragment);                 Log.d("tag", "title is 111 " + bundle.get("title"));                  transaction.commit();             }          };         return onItemClickCallback;     }      @Override     public void onAttachFragment(Fragment childFragment) {         super.onAttachFragment(childFragment);      }      public void sortByPopularity() {         RetrofitClient.getApiService().getPopularList(getString(R.string.api_key)).enqueue(new Callback<BasePojo>() {             @Override             public void onResponse(Call<BasePojo> call, Response<BasePojo> response) {                 BasePojo basePojo = response.body();                 list.addAll(basePojo.getResults());                 recyclerView.getAdapter().notifyDataSetChanged();             }              @Override             public void onFailure(Call<BasePojo> call, Throwable t) {                 Log.d("tag", "Response failed" + t.toString());              }         }); }  } 

And here is an error

05-09 12:48:26.915 5775-5775/com.borisruzanov.popularmovies E/AndroidRuntime: FATAL EXCEPTION: main Process: com.borisruzanov.popularmovies, PID: 5775 java.lang.IllegalStateException: Fragment ListFragment{6dbd6de} not attached to a context.     at android.support.v4.app.Fragment.requireContext(Fragment.java:614)     at android.support.v4.app.Fragment.getResources(Fragment.java:678)     at android.support.v4.app.Fragment.getString(Fragment.java:700)     at com.borisruzanov.popularmovies.ListFragment.sortByPopularity(ListFragment.java:110)     at com.borisruzanov.popularmovies.MainActivity.onOptionsItemSelected(MainActivity.java:47)     at android.app.Activity.onMenuItemSelected(Activity.java:3204)     at android.support.v4.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:407)     at android.support.v7.app.AppCompatActivity.onMenuItemSelected(AppCompatActivity.java:195)     at android.support.v7.view.WindowCallbackWrapper.onMenuItemSelected(WindowCallbackWrapper.java:108)     at android.support.v7.view.WindowCallbackWrapper.onMenuItemSelected(WindowCallbackWrapper.java:108)     at android.support.v7.app.ToolbarActionBar$2.onMenuItemClick(ToolbarActionBar.java:63)     at android.support.v7.widget.Toolbar$1.onMenuItemClick(Toolbar.java:203)     at android.support.v7.widget.ActionMenuView$MenuBuilderCallback.onMenuItemSelected(ActionMenuView.java:780)     at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)     at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:171)     at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:973)     at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:963)     at android.support.v7.widget.ActionMenuView.invokeItem(ActionMenuView.java:624)     at android.support.v7.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:150)     at android.view.View.performClick(View.java:5610)     at android.view.View$PerformClick.run(View.java:22265)     at android.os.Handler.handleCallback(Handler.java:751)     at android.os.Handler.dispatchMessage(Handler.java:95)     at android.os.Looper.loop(Looper.java:154)     at android.app.ActivityThread.main(ActivityThread.java:6077)     at java.lang.reflect.Method.invoke(Native Method)     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756) 

Thank you very much for your time and help. If my question looks not well please make a note and I will teach how to ask questions better

Answer 1

In my case, this problem occurred when I was calling getString()

changing this calls to getActivity().getString() solved the problem.