Fragment Layout components are null

Question

I have created a DrawerLayout(containing a NavView for a menu) fragment and named it NavMenuFragment and i've tried implementing it into my mainActivity.java class without succession. After running the debugger i noticed that all of the layouts from the fragment's layout file do not get initialized thus equaling to null. Any ideas on why this is happening? Here are the .java class and the .xml file from the fragment :

Fragment.java:

public class NavMenuFragment extends Fragment {

// NavMenu member vars
private DrawerLayout mDrawerLayout;
private NavigationView navigationView;
private ActionBarDrawerToggle mToggle; // Button for toggling the side menu

// Keeps the position of the previously selected menu item(0 : Home)
int position = 0;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View view = inflater.inflate(R.layout.fragment_nav_menu,null);
    mDrawerLayout = view.findViewById(R.id.drawerLayout);
    navigationView = view.findViewById(R.id.nav_view);

    return view;
}

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    mToggle = new ActionBarDrawerToggle(getActivity(),mDrawerLayout,R.string.drawer_open,R.string.drawer_closed); // Instantiating our button

    // Sets the default selected menu item, to the Home item
    navigationView.getMenu().findItem(R.id.nav_home).setChecked(true);

    // Used to help on check and uncheck menu items when the user clicks on them
    final List<MenuItem> items = new ArrayList<>();
    Menu menu;
    menu = navigationView.getMenu();

    // Fill the list with all the menu items
    for(int i=0; i<menu.size();i++) {
        items.add(menu.getItem(i));
    }

    Toast.makeText(getActivity(), "size:" + items.size(), Toast.LENGTH_SHORT).show();

    // When an item inside the NavView gets clicked, then handle the event...
    navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {

        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {

            switch (item.getItemId()) {
                case R.id.nav_home:
                    mDrawerLayout.closeDrawer(Gravity.START);
                    break;
                case R.id.nav_UserBoxGLB:
                    break;
                case R.id.nav_UserBoxJP:
                    break;
                case R.id.nav_settings:
                    break;
                case R.id.nav_feedback:
                    break;
                case R.id.nav_contact_us:
                    break;
                case R.id.nav_donate:
                    // Open the website's URL in a browser window
                    Intent intent = new Intent();
                    intent.setAction(Intent.ACTION_VIEW);
                    intent.addCategory(Intent.CATEGORY_BROWSABLE);
                    intent.setData(Uri.parse("http://www.google.com"));
                    startActivity(intent);
                    break;
                case R.id.nav_about:
                    break;
                default:
                    return onNavigationItemSelected(item);
            }
            items.get(position).setChecked(false);
            item.setChecked(true);
            mDrawerLayout.closeDrawers();
            return false;
        }
    });

    mDrawerLayout.addDrawerListener(mToggle);
    // Set the hamburger icon's color
    mToggle.getDrawerArrowDrawable().setColor(getResources().getColor(R.color.NavActionBarTextColor));
    mToggle.syncState();
}

// When an item from the Action Bar gets tapped, then...
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    return mToggle.onOptionsItemSelected(item) || onOptionsItemSelected(item);
}
}

fragment.xml:

 <android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorPrimary"
    android:id="@+id/drawerLayout">

    <!-- The actual side menu Nav View -->
    <android.support.design.widget.NavigationView
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        app:headerLayout="@layout/navigation_header"
        app:menu="@menu/navigation_menu"
        android:id="@+id/nav_view">

    </android.support.design.widget.NavigationView>

</android.support.v4.widget.DrawerLayout>

Answer 1

• RETURN VIEW
• Pass VIEW Object instead of getView().
• FrameLayout- No need.

Try this way

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) 
{
        View view = inflater.inflate(R.layout.fragment_nav_menu, null);
        mDrawerLayout = view.findViewById(R.id.drawerLayout);
         ..................................
        navigationView = view.findViewById(R.id.nav_view);

        return view;
}