title: How to create sub menu in Navigation drawer
body: <pre><code>public class NavigationDrawerFragment extends Fragment  {
  
      /**
       * Remember the position of the selected item.
       */
      private static final String STATE_SELECTED_POSITION = "selected_navigation_drawer_position";
  
      /**
       * Per the design guidelines, you should show the drawer on launch until the
       * user manually expands it. This shared preference tracks this.
       */
      private static final String PREF_USER_LEARNED_DRAWER = "navigation_drawer_learned";
  
      /**
       * A pointer to the current callbacks instance (the Activity).
       */
      private NavigationDrawerCallbacks mCallbacks;
  
      /**
       * Helper component that ties the action bar to the navigation drawer.
       */
      private ActionBarDrawerToggle mDrawerToggle;
  
      private DrawerLayout mDrawerLayout;
      private ExpandableListView mDrawerListView;
      private View mFragmentContainerView;
  
      List&lt;String&gt; groupList;
      List&lt;String&gt; childList;
      Map&lt;String, List&lt;String&gt;&gt; laptopCollection;
  
      private int mCurrentSelectedPosition = 0;
      private boolean mFromSavedInstanceState;
      private boolean mUserLearnedDrawer;
  
      public NavigationDrawerFragment() {
      }
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
  
          // Read in the flag indicating whether or not the user has demonstrated
          // awareness of the
          // drawer. See PREF_USER_LEARNED_DRAWER for details.
          SharedPreferences sp = PreferenceManager
                  .getDefaultSharedPreferences(getActivity());
          mUserLearnedDrawer = sp.getBoolean(PREF_USER_LEARNED_DRAWER, false);
  
          if (savedInstanceState != null) {
              mCurrentSelectedPosition = savedInstanceState
                      .getInt(STATE_SELECTED_POSITION);
              mFromSavedInstanceState = true;
          }
  
          // Select either the default item (0) or the last selected item.
          selectItem(mCurrentSelectedPosition);
      }
  
      @Override
      public void onActivityCreated(Bundle savedInstanceState) {
          super.onActivityCreated(savedInstanceState);
          // Indicate that this fragment would like to influence the set of
          // actions in the action bar.
          setHasOptionsMenu(true);
      }
  
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,
              Bundle savedInstanceState) {
  
  
           createGroupList();
  
              createCollection();
  
              mDrawerListView = (ExpandableListView) inflater.inflate(
                      R.layout.fragment_navigation_drawer, container, false);
              final ExpandableListAdapter expListAdapter = new ExpandableListAdapter(
                      getActivity(), groupList, laptopCollection);
              mDrawerListView.setAdapter(expListAdapter);
  
              //setGroupIndicatorToRight();
  
              mDrawerListView.setOnChildClickListener(new OnChildClickListener() {
  
                  public boolean onChildClick(ExpandableListView parent, View v,
                          int groupPosition, int childPosition, long id) {
                      final String selected = (String) expListAdapter.getChild(
                              groupPosition, childPosition);
                      Toast.makeText(getActivity().getBaseContext(), selected, Toast.LENGTH_LONG)
                              .show();
  
                      return true;
                  }
              });
              return mFragmentContainerView;
  
  
          }
  
          private void createGroupList() {
              groupList = new ArrayList&lt;String&gt;();
              groupList.add("HP");
              groupList.add("Dell");
              groupList.add("Lenovo");
              groupList.add("Sony");
              groupList.add("HCL");
              groupList.add("Samsung");
          }
  
          private void createCollection() {
              // preparing laptops collection(child)
              String[] hpModels = { "HP Pavilion G6-2014TX", "ProBook HP 4540",
                      "HP Envy 4-1025TX" };
              String[] hclModels = { "HCL S2101", "HCL L2102", "HCL V2002" };
              String[] lenovoModels = { "IdeaPad Z Series", "Essential G Series",
                      "ThinkPad X Series", "Ideapad Z Series" };
              String[] sonyModels = { "VAIO E Series", "VAIO Z Series",
                      "VAIO S Series", "VAIO YB Series" };
              String[] dellModels = { "Inspiron", "Vostro", "XPS" };
              String[] samsungModels = { "NP Series", "Series 5", "SF Series" };
  
              laptopCollection = new LinkedHashMap&lt;String, List&lt;String&gt;&gt;();
  
              for (String laptop : groupList) {
                  if (laptop.equals("HP")) {
                      loadChild(hpModels);
                  } else if (laptop.equals("Dell"))
                      loadChild(dellModels);
                  else if (laptop.equals("Sony"))
                      loadChild(sonyModels);
                  else if (laptop.equals("HCL"))
                      loadChild(hclModels);
                  else if (laptop.equals("Samsung"))
                      loadChild(samsungModels);
                  else
                      loadChild(lenovoModels);
  
                  laptopCollection.put(laptop, childList);
              }
          }
  
          private void loadChild(String[] laptopModels) {
              childList = new ArrayList&lt;String&gt;();
              for (String model : laptopModels)
                  childList.add(model);
          }
  
          @SuppressWarnings("unused")
          private void setGroupIndicatorToRight() {
              /* Get the screen width */
              DisplayMetrics dm = new DisplayMetrics();
              getActivity().getWindowManager().getDefaultDisplay().getMetrics(dm);
              int width = dm.widthPixels;
  
              mDrawerListView.setIndicatorBounds(width - getDipsFromPixel(35), width
                      - getDipsFromPixel(5));
          }
  
          // Convert pixel to dip
          public int getDipsFromPixel(float pixels) {
              // Get the screen's density scale
              final float scale = getResources().getDisplayMetrics().density;
              // Convert the dps to pixels, based on density scale
              return (int) (pixels * scale + 0.5f);
          }
  
  
  
  
  
  
  
  
  
          /*mDrawerListView = (ExpandableListView) inflater.inflate(
                  R.layout.fragment_navigation_drawer, container, false);
          mDrawerListView
                  .setOnItemClickListener(new AdapterView.OnItemClickListener() {
                      @Override
                      public void onItemClick(AdapterView&lt;?&gt; parent, View view,
                              int position, long id) {
                          selectItem(position);
                      }
                  });
          mDrawerListView.setAdapter(new ArrayAdapter&lt;String&gt;(getActionBar()
                  .getThemedContext(),
                  android.R.layout.simple_list_item_activated_1,
                  android.R.id.text1, new String[] {
                          getString(R.string.title_section1),
                          getString(R.string.title_section2),
                          getString(R.string.title_section3), }));
          mDrawerListView.setItemChecked(mCurrentSelectedPosition, true);*/
  
  
  
      public boolean isDrawerOpen() {
          return mDrawerLayout != null
                  &amp;&amp; mDrawerLayout.isDrawerOpen(mFragmentContainerView);
      }
  
      /**
       * Users of this fragment must call this method to set up the navigation
       * drawer interactions.
       *
       * @param fragmentId
       *            The android:id of this fragment in its activity's layout.
       * @param drawerLayout
       *            The DrawerLayout containing this fragment's UI.
       */
      public void setUp(int fragmentId, DrawerLayout drawerLayout) {
          mFragmentContainerView = getActivity().findViewById(fragmentId);
          mDrawerLayout = drawerLayout;
  
          // set a custom shadow that overlays the main content when the drawer
          // opens
          mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow,
                  GravityCompat.START);
          // set up the drawer's list view with items and click listener
  
          ActionBar actionBar = getActionBar();
          actionBar.setDisplayHomeAsUpEnabled(true);
          actionBar.setHomeButtonEnabled(true);
  
          // ActionBarDrawerToggle ties together the the proper interactions
          // between the navigation drawer and the action bar app icon.
          mDrawerToggle = new ActionBarDrawerToggle(getActivity(), /* host Activity */
          mDrawerLayout, /* DrawerLayout object */
          R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */
          R.string.navigation_drawer_open, /*
                                           * "open drawer" description for
                                           * accessibility
                                           */
          R.string.navigation_drawer_close /*
                                           * "close drawer" description for
                                           * accessibility
                                           */
          ) {
              @Override
              public void onDrawerClosed(View drawerView) {
                  super.onDrawerClosed(drawerView);
                  if (!isAdded()) {
                      return;
                  }
  
                  getActivity().invalidateOptionsMenu(); // calls
                                                          // onPrepareOptionsMenu()
              }
  
              @Override
              public void onDrawerOpened(View drawerView) {
                  super.onDrawerOpened(drawerView);
                  if (!isAdded()) {
                      return;
                  }
  
                  if (!mUserLearnedDrawer) {
                      // The user manually opened the drawer; store this flag to
                      // prevent auto-showing
                      // the navigation drawer automatically in the future.
                      mUserLearnedDrawer = true;
                      SharedPreferences sp = PreferenceManager
                              .getDefaultSharedPreferences(getActivity());
                      sp.edit().putBoolean(PREF_USER_LEARNED_DRAWER, true)
                              .apply();
                  }
  
                  getActivity().invalidateOptionsMenu(); // calls
                                                          // onPrepareOptionsMenu()
              }
          };
  
          // If the user hasn't 'learned' about the drawer, open it to introduce
          // them to the drawer,
          // per the navigation drawer design guidelines.
          if (!mUserLearnedDrawer &amp;&amp; !mFromSavedInstanceState) {
              mDrawerLayout.openDrawer(mFragmentContainerView);
          }
  
          // Defer code dependent on restoration of previous instance state.
          mDrawerLayout.post(new Runnable() {
              @Override
              public void run() {
                  mDrawerToggle.syncState();
              }
          });
  
          mDrawerLayout.setDrawerListener(mDrawerToggle);
      }
  
      private void selectItem(int position) {
          mCurrentSelectedPosition = position;
          if (mDrawerListView != null) {
              mDrawerListView.setItemChecked(position, true);
          }
          if (mDrawerLayout != null) {
              mDrawerLayout.closeDrawer(mFragmentContainerView);
          }
          if (mCallbacks != null) {
              mCallbacks.onNavigationDrawerItemSelected(position);
          }
      }
  
      @Override
      public void onAttach(Activity activity) {
          super.onAttach(activity);
          try {
              mCallbacks = (NavigationDrawerCallbacks) activity;
          } catch (ClassCastException e) {
              throw new ClassCastException(
                      "Activity must implement NavigationDrawerCallbacks.");
          }
      }
  
      @Override
      public void onDetach() {
          super.onDetach();
          mCallbacks = null;
      }
  
      @Override
      public void onSaveInstanceState(Bundle outState) {
          super.onSaveInstanceState(outState);
          outState.putInt(STATE_SELECTED_POSITION, mCurrentSelectedPosition);
      }
  
      @Override
      public void onConfigurationChanged(Configuration newConfig) {
          super.onConfigurationChanged(newConfig);
          // Forward the new configuration the drawer toggle component.
          mDrawerToggle.onConfigurationChanged(newConfig);
      }
  
      @Override
      public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
          // If the drawer is open, show the global app actions in the action bar.
          // See also
          // showGlobalContextActionBar, which controls the top-left area of the
          // action bar.
          if (mDrawerLayout != null &amp;&amp; isDrawerOpen()) {
              inflater.inflate(R.menu.global, menu);
              showGlobalContextActionBar();
          }
          super.onCreateOptionsMenu(menu, inflater);
      }
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          if (mDrawerToggle.onOptionsItemSelected(item)) {
              return true;
          }
  
          if (item.getItemId() == R.id.action_example) {
              Toast.makeText(getActivity(), "Example action.", Toast.LENGTH_SHORT)
                      .show();
              return true;
          }
  
          return super.onOptionsItemSelected(item);
      }
  
      /**
       * Per the navigation drawer design guidelines, updates the action bar to
       * show the global app 'context', rather than just what's in the current
       * screen.
       */
      private void showGlobalContextActionBar() {
          ActionBar actionBar = getActionBar();
          actionBar.setDisplayShowTitleEnabled(true);
          actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
          actionBar.setTitle(R.string.app_name);
      }
  
      private ActionBar getActionBar() {
          return getActivity().getActionBar();
      }
  
      /**
       * Callbacks interface that all activities using this fragment must
       * implement.
       */
      public static interface NavigationDrawerCallbacks {
          /**
           * Called when an item in the navigation drawer is selected.
           */
          void onNavigationDrawerItemSelected(int position);
      }
  }
  </code></pre>
  
  <p>I'm getting errors and its not working with expandable list view.
  I've been working on this for five days and not getting any help on internet.
  Please help me!</p>