title: Android - How to change fragments in the Navigation Drawer
body: <p>I'm fairly new to Android programming, but have been doing pretty well until now. I've read a lot of answers to this question but can't seem to make mine work. Basically what I have is a MainActivity with a Navigation Drawer. I have two fragments correctly initialized with corresponding fragment layout xmls. Currently I can get my first fragment to show up when the app starts and when I click on each item in the drawer, the titles change; however, the fragment stays the same. Any suggestions? What I believe to be relevant code is below (not shown is the code for the NavigationDrawerFragment.java with the necessary code automatically built by Eclipse). Thanks in advance!</p>
  
  <pre><code>public class MainActivity extends Activity
  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;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
  
      mNavigationDrawerFragment = (NavigationDrawerFragment)
              getFragmentManager().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();
      fragmentManager.beginTransaction()
              .replace(R.id.content_frame, PlaceholderFragment.newInstance(position + 1))
              .commit();
  
  }
  
  public void onSectionAttached(int number) {
      switch (number) {
          case 1:
              mTitle = getString(R.string.title_home);
              break;
          case 2:
              mTitle = getString(R.string.title_infodirect);
              break;
          case 3:
              mTitle = getString(R.string.title_trailmap);
              break;
          case 4:
              mTitle = getString(R.string.title_poi);
              break;
          case 5:
              mTitle = getString(R.string.title_photomap);
              break;
          case 6:
              mTitle = getString(R.string.title_report);
              break;
          case 7:
              mTitle = getString(R.string.title_rulesreg);
  
      }
  }
  
  public void restoreActionBar() {
      ActionBar actionBar = getActionBar();
      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.overview, 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();
      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_home, container, false);
          return rootView;
      }
  
      @Override
      public void onAttach(Activity activity) {
          super.onAttach(activity);
          ((MainActivity) activity).onSectionAttached(
                  getArguments().getInt(ARG_SECTION_NUMBER));
      }
  }
  
  public static class InfoDirectFragment 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 InfoDirectFragment newInstance(int sectionNumber) {
          InfoDirectFragment fragment = new InfoDirectFragment();
          Bundle args = new Bundle();
          args.putInt(ARG_SECTION_NUMBER, sectionNumber);
          fragment.setArguments(args);
          return fragment;
      }
  
      public InfoDirectFragment() {
      }
  
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,
              Bundle savedInstanceState) {
          View rootView = inflater.inflate(R.layout.fragment_infodirect, container, false);
          return rootView;
      }
  
      @Override
      public void onAttach(Activity activity) {
          super.onAttach(activity);
          ((MainActivity) activity).onSectionAttached(
                  getArguments().getInt(ARG_SECTION_NUMBER));
      }
  }
  }
  </code></pre>