title: How to add ExpandableListView in android studio 1.2 under my CategoryFragment?
body: <p>i use android studio 1.2 and i just want to know how to add submenu or what they call ExpandableListView under my category?</p>
  
  <p>hope someone can help me..</p>
  
  <p>here is my code..</p>
  
  <p>MainActivity.java</p>
  
  <pre><code>package com.example.administrator.mosbeau;
  
  import android.app.Activity;
  import android.support.v7.app.ActionBarActivity;
  import android.support.v7.app.ActionBar;
  import android.app.Fragment;
  import android.app.FragmentManager;
  import android.os.Bundle;
  import android.view.LayoutInflater;
  import android.view.Menu;
  import android.view.MenuItem;
  import android.view.View;
  import android.view.ViewGroup;
  import android.support.v4.widget.DrawerLayout;
  
  
  public class MainActivity extends ActionBarActivity
          implements NavigationDrawerFragment.NavigationDrawerCallbacks {
  
      /**
       * Fragment managing the behaviors, interactions and presentation of the navigation drawer.
       */
      private NavigationDrawerFragment mNavigationDrawerFragment;
  
      /**
       * Used to store the last screen title. For use in {@link #restoreActionBar()}.
       */
      private CharSequence mTitle;
  
      Boolean InternetAvailable = false;
      Seocnd detectconnection;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
  
          detectconnection = new Seocnd(this);
          InternetAvailable = detectconnection.InternetConnecting();
          if (InternetAvailable) {
          } else {
              NointernetFragment fragment = new NointernetFragment();
              FragmentManager fragmentManager = getFragmentManager();
              fragmentManager.beginTransaction()
                      .replace(R.id.container, fragment)
                      .commit();
          }
  
          mNavigationDrawerFragment = (NavigationDrawerFragment)
                  getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);
          mTitle = getTitle();
  
          // Set up the drawer.
          mNavigationDrawerFragment.setUp(
                  R.id.navigation_drawer,
                  (DrawerLayout) findViewById(R.id.drawer_layout));
      }
  
      @Override
      public void onNavigationDrawerItemSelected(int position) {
          // update the main content by replacing fragments
  
          FragmentManager fragmentManager = getFragmentManager();
  
          // NEW STUFF
          if(position == 0){
              fragmentManager.beginTransaction()
                      .replace(R.id.container, HomeFragment.newInstance())
                      .commit();
          }
          else if (position == 1){
              fragmentManager.beginTransaction()
                      .replace(R.id.container, CategoryFragment.newInstance())
                      .commit();
          }
          else if (position == 2){
              fragmentManager.beginTransaction()
                      .replace(R.id.container, AccountFragment.newInstance())
                      .commit();
          }
          else if (position == 3){
              fragmentManager.beginTransaction()
                      .replace(R.id.container, ReferFragment.newInstance())
                      .commit();
          }
          else if (position == 4){
              fragmentManager.beginTransaction()
                      .replace(R.id.container, AboutFragment.newInstance())
                      .commit();
          }
          else if (position == 5){
              fragmentManager.beginTransaction()
                      .replace(R.id.container, PolicyFragment.newInstance())
                      .commit();
          }
          else if (position == 6){
              fragmentManager.beginTransaction()
                      .replace(R.id.container, TermsFragment.newInstance())
                      .commit();
          }
          else if (position == 7){
              fragmentManager.beginTransaction()
                      .replace(R.id.container, ContactusFragment.newInstance())
                      .commit();
          }
      }
  
      public void onSectionAttached(int number) {
          switch (number) {
              case 1:
                  mTitle = getString(R.string.title_home);
                  break;
              case 2:
                  mTitle = getString(R.string.title_category);
                  break;
              case 3:
                  mTitle = getString(R.string.title_login);
                  break;
              case 4:
                  mTitle = getString(R.string.title_register);
                  break;
              case 5:
                  mTitle = getString(R.string.title_myaccount);
                  break;
              case 6:
                  mTitle = getString(R.string.title_referafriend);
                  break;
              case 7:
                  mTitle = getString(R.string.title_about);
                  break;
              case 8:
                  mTitle = getString(R.string.title_privacypocity);
                  break;
              case 9:
                  mTitle = getString(R.string.title_shippingterms);
                  break;
              case 10:
                  mTitle = getString(R.string.title_contactus);
                  break;
          }
      }
  
      @SuppressWarnings("deprecation")
      public void restoreActionBar() {
          ActionBar actionBar = getSupportActionBar();
          actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
          actionBar.setDisplayShowTitleEnabled(true);
          actionBar.setTitle(mTitle);
      }
  
  
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          if (!mNavigationDrawerFragment.isDrawerOpen()) {
              // Only show items in the action bar relevant to this screen
              // if the drawer is not showing. Otherwise, let the drawer
              // decide what to show in the action bar.
              getMenuInflater().inflate(R.menu.main, menu);
              restoreActionBar();
              return true;
          }
          return super.onCreateOptionsMenu(menu);
      }
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          // Handle action bar item clicks here. The action bar will
          // automatically handle clicks on the Home/Up button, so long
          // as you specify a parent activity in AndroidManifest.xml.
          int id = item.getItemId();
  
          //noinspection SimplifiableIfStatement
          if (id == R.id.action_settings) {
              return true;
          }
  
          return super.onOptionsItemSelected(item);
      }
  
      /**
       * A placeholder fragment containing a simple view.
       */
      public static class PlaceholderFragment extends Fragment {
          /**
           * The fragment argument representing the section number for this
           * fragment.
           */
          private static final String ARG_SECTION_NUMBER = "section_number";
  
          /**
           * Returns a new instance of this fragment for the given section
           * number.
           */
          public static PlaceholderFragment newInstance(int sectionNumber) {
              PlaceholderFragment fragment = new PlaceholderFragment();
              Bundle args = new Bundle();
              args.putInt(ARG_SECTION_NUMBER, sectionNumber);
              fragment.setArguments(args);
              return fragment;
          }
  
          public PlaceholderFragment() {
          }
  
          @Override
          public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                   Bundle savedInstanceState) {
              View rootView = inflater.inflate(R.layout.fragment_main, container, false);
              return rootView;
          }
  
          @Override
          public void onAttach(Activity activity) {
              super.onAttach(activity);
              ((MainActivity) activity).onSectionAttached(
                      getArguments().getInt(ARG_SECTION_NUMBER));
          }
  
      }
  
  }
  </code></pre>
  
  <p>NavigationDrawerFragment.java</p>
  
  <pre><code>package com.example.administrator.mosbeau;
  
  import android.support.v7.app.ActionBarActivity;
  import android.app.Activity;
  import android.support.v7.app.ActionBar;
  import android.support.v4.app.Fragment;
  import android.support.v7.app.ActionBarDrawerToggle;
  import android.support.v4.view.GravityCompat;
  import android.support.v4.widget.DrawerLayout;
  import android.content.SharedPreferences;
  import android.content.res.Configuration;
  import android.os.Bundle;
  import android.preference.PreferenceManager;
  import android.view.LayoutInflater;
  import android.view.Menu;
  import android.view.MenuInflater;
  import android.view.MenuItem;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.AdapterView;
  import android.widget.ArrayAdapter;
  import android.widget.ListView;
  import android.widget.Toast;
  
  /**
   * Fragment used for managing interactions for and presentation of a navigation drawer.
   * See the &lt;a href="https://developer.android.com/design/patterns/navigation-drawer.html#Interaction"&gt;
   * design guidelines&lt;/a&gt; for a complete explanation of the behaviors implemented here.
   */
  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 ListView mDrawerListView;
      private View mFragmentContainerView;
  
      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) {
          mDrawerListView = (ListView) 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_home),
                          getString(R.string.title_category),
                          getString(R.string.title_myaccount),
                          getString(R.string.title_referafriend),
                          getString(R.string.title_about),
                          getString(R.string.title_privacypocity),
                          getString(R.string.title_shippingterms),
                          getString(R.string.title_contactus),
                  }));
          mDrawerListView.setItemChecked(mCurrentSelectedPosition, true);
          return mDrawerListView;
      }
  
      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.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().supportInvalidateOptionsMenu(); // 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().supportInvalidateOptionsMenu(); // 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 ((ActionBarActivity) getActivity()).getSupportActionBar();
      }
  
      /**
       * 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>no idea where to add  ExpandableListView in the code..</p>
  
  <p>activity_main.xml</p>
  
  <p>
  </p>
  
  <pre><code>&lt;!-- As the main content view, the view below consumes the entire
       space available using match_parent in both dimensions. --&gt;
  &lt;FrameLayout android:id="@+id/container" android:layout_width="match_parent"
      android:layout_height="match_parent" /&gt;
  
  &lt;!-- android:layout_gravity="start" tells DrawerLayout to treat
       this as a sliding drawer on the left side for left-to-right
       languages and on the right side for right-to-left languages.
       If you're not building against API 17 or higher, use
       android:layout_gravity="left" instead. --&gt;
  &lt;!-- The drawer is given a fixed width in dp and extends the full height of
       the container. --&gt;
  &lt;fragment android:id="@+id/navigation_drawer"
  android:layout_width="@dimen/navigation_drawer_width" android:layout_height="match_parent"
  android:layout_gravity="start"
  android:name="com.example.administrator.mosbeau.NavigationDrawerFragment"
  tools:layout="@layout/fragment_navigation_drawer" /&gt;
  </code></pre>
  
  <p></p>
  
  <p>fragment_main.xml</p>
  
  <pre><code>&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
      android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
      android:paddingRight="@dimen/activity_horizontal_margin"
      android:paddingTop="@dimen/activity_vertical_margin"
      android:paddingBottom="@dimen/activity_vertical_margin"
      tools:context=".MainActivity$PlaceholderFragment"&gt;
  
      &lt;TextView android:id="@+id/section_label" android:layout_width="wrap_content"
          android:layout_height="wrap_content"/&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>fragment_navigation_drawer.xml</p>
  
  <pre><code>&lt;ListView xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
      android:layout_height="match_parent" android:choiceMode="singleChoice"
      android:divider="@android:color/transparent" android:dividerHeight="0dp"
      android:background="#ffffff" tools:context=".NavigationDrawerFragment"
      android:listSelector="#eeeeee" /&gt;
  </code></pre>
  
  <p>please help me.. im new to android..</p>
  
  <p>i use the built in navigation drawer activity of android studio..</p>
  
  <p>check below image for sample of what i want..</p>
  
  <p><a href="https://i.stack.imgur.com/sUKD7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/sUKD7.png" alt="enter image description here"></a></p>