Java – The navigation menu fragment was unable to initialize the components whose layout

I’ve created a navigation menu fragment for my app so that I can use it in all my activities. However, when I run the app, the menu doesn’t work, either when I click the hamburger icon or pull from left to right. So I decided to use the debugger and I found that none of my fragment’s layout components were initialized in the fragment’s class. Can you help me figure out why this is happening and how to fix it? Here is my fragment.java class and my fragment_layout.xml file:

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

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

 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 layout .xml:

 <android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_gravity="left"
    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>

You’re
doing it wrong
If you want to use the same drawer navigation for all fragments, then
You can make a drawer navigation in your main activity and open a fragment from that drawer navigation.
This is tutorial