Recycler View Not Showing

Question

I have been making an app that uses a recycler view in a navigation drawer. Why the contents of the recycler view are not showing up. The view is definitely there as I can see the scroll shadows. I am not sure what I have done wrong, as the app does not crash when it is run.

Navigation Drawer Fragment:

public class NavigationDrawerFragment extends android.support.v4.app.Fragment {      public static final String PREF_FILE_NAME = "testPref";     public static final String KEY_USER_LEARNED_DRAWER = "user_learned_drawer";     private RecyclerView mRecyclerView;     private ActionBarDrawerToggle mDrawerToggle;     private DrawerLayout mDrawerLayout;     private View containerView;     private Boolean mUserLearnedDrawer;     private Boolean mFromSavedInstanceState;     private DrawerAdapter adapter;      public NavigationDrawerFragment() {         mFromSavedInstanceState = false;     }       @Override     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         mUserLearnedDrawer = Boolean.valueOf(readFromPreferences(getActivity(), KEY_USER_LEARNED_DRAWER, "false"));         if (savedInstanceState != null){             mFromSavedInstanceState = true;         }     }      @Override     public View onCreateView(LayoutInflater inflater, ViewGroup container,                              Bundle savedInstanceState) {         // Inflate the layout for this fragment         View layout = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);         mRecyclerView = (RecyclerView) layout.findViewById(R.id.drawerList);         adapter = new DrawerAdapter(getActivity(), getData());         mRecyclerView.setAdapter(adapter);         mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));         return layout;     }      public static List<DrawerRow> getData(){         List<DrawerRow> data = new ArrayList<>();         int icons[] = {R.drawable.ic_launcher,R.drawable.ic_launcher,R.drawable.ic_launcher,R.drawable.ic_launcher};         String titles[] = {"Link 1","Link 2","Link 3","Link 4"};         for (int i = 0 ; i < titles.length && i < icons.length; i++){             DrawerRow current = new DrawerRow();             current.iconId = icons[i];             current.title = titles[i];             data.add(current);         }          return data;     }      public void setUp(int fragmentId, DrawerLayout drawerLayout, Toolbar toolbar) {         containerView = getActivity().findViewById(fragmentId);         mDrawerLayout = drawerLayout;         mDrawerToggle = new ActionBarDrawerToggle(getActivity(), drawerLayout, toolbar, R.string.drawerOpen, R.string.drawerClosed){              @Override             public void onDrawerOpened(View drawerView) {                 super.onDrawerOpened(drawerView);                 if(!mUserLearnedDrawer){                     mUserLearnedDrawer = true;                     saveToPreferences(getActivity(),KEY_USER_LEARNED_DRAWER, mUserLearnedDrawer+"");                 }                 getActivity().invalidateOptionsMenu();             }              @Override             public void onDrawerClosed(View drawerView) {                 super.onDrawerClosed(drawerView);                 getActivity().invalidateOptionsMenu();             }         };          if(!mUserLearnedDrawer && !mFromSavedInstanceState){             mDrawerLayout.openDrawer(containerView);         }          mDrawerLayout.setDrawerListener(mDrawerToggle);         mDrawerLayout.post(new Runnable() {             @Override             public void run() {                 mDrawerToggle.syncState();             }         });     }      public void saveToPreferences(Context context, String prefName, String prefValue){         SharedPreferences sharedPreferences = context.getSharedPreferences(PREF_FILE_NAME, Context.MODE_PRIVATE);         SharedPreferences.Editor mEditor = sharedPreferences.edit();         mEditor.putString(prefName, prefValue);         mEditor.apply();     }      public static String readFromPreferences(Context context, String prefName, String defaultValue){         SharedPreferences sharedPreferences = context.getSharedPreferences(PREF_FILE_NAME, Context.MODE_PRIVATE);         return sharedPreferences.getString(prefName,defaultValue);     } } 

Adapter:

public class DrawerAdapter extends RecyclerView.Adapter<DrawerAdapter.MyViewHolder>{      private LayoutInflater inflator;     List<DrawerRow> data = Collections.EMPTY_LIST;      public DrawerAdapter(FragmentActivity activity, List<DrawerRow> data) {         inflator = LayoutInflater.from(activity);         this.data = data;     }       @Override     public MyViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {         View view = inflator.inflate(R.layout.nav_drawer_row , viewGroup,false);         MyViewHolder holder = new MyViewHolder(view);         return holder;     }      @Override     public void onBindViewHolder(MyViewHolder viewHolder, int i) {         DrawerRow current = data.get(i);         viewHolder.title.setText(current.title);         viewHolder.icon.setImageResource(current.iconId);     }      @Override     public int getItemCount() {         return 0;     }      class MyViewHolder extends RecyclerView.ViewHolder{         ImageView icon;         TextView title;          public MyViewHolder(View itemView) {             super(itemView);             icon = (ImageView) itemView.findViewById(R.id.list_icon);             title = (TextView) itemView.findViewById(R.id.list_text);         }     } } 

Drawer Row:

public class DrawerRow {     int iconId;     String title; } 

Layout:

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:id="@+id/drawerLayout">      <!--Main Content -->     <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"         android:layout_width="match_parent"         android:layout_height="match_parent"         android:orientation="vertical">          <include             android:id="@+id/app_bar"             layout="@layout/app_bar" />          <TextView             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="New Text" />      </LinearLayout>      <!--Nav Drawer -->     <fragment         android:layout_width="@dimen/nav_drawer_width"         android:layout_height="match_parent"         android:layout_gravity="start"         android:name="uk.co.clickcomputing.hhscweatherstation.NavigationDrawerFragment"         android:id="@+id/fragment_navigation_drawer"/>  </android.support.v4.widget.DrawerLayout> 

Drawer Row:

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:orientation="horizontal" android:layout_width="match_parent"     android:layout_height="match_parent">      <ImageView         android:padding="@dimen/list_padding"         android:id="@+id/list_icon"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_gravity="center_vertical"         android:src="@drawable/ic_launcher"/>      <TextView         android:padding="@dimen/list_padding"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_gravity="center_vertical"         android:text="New Text"         android:id="@+id/list_text" /> </LinearLayout> 

Navigation Drawer Fragment Layout:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:background="#eee"     android:orientation="vertical">          <ImageView             android:layout_width="match_parent"             android:layout_height="140dp"             android:layout_marginBottom="8dp"             android:contentDescription="@string/nav_drawer_img_desciption"             android:scaleType="centerCrop"             android:src="@drawable/nav_drawer" />              <android.support.v7.widget.RecyclerView             android:layout_width="match_parent"             android:layout_height="wrap_content"             android:id="@+id/drawerList">              </android.support.v7.widget.RecyclerView>     </LinearLayout> 

Answer 1

The issue is that you are returning the item count as 0 which tells that there is no rows to show. You should return the size of the List as shown below.

    @Override     public int getItemCount() {         return data.size();     }