Ich habe Mühe, die Elemente der Navigations-Schublade zu registrieren und zu starten und beabsichtige, eine neue Aktivität durchzuführen. Die Schublade öffnet sich gut und wird korrekt angezeigt, aber nichts passiert, wenn ich auf die Elemente in der Liste klicke. Hier ist mein Code, der aus den Google-Tutorials stammt.

mTitle = mDrawerTitle = getTitle();
           mTitles = getResources().getStringArray(R.array.menu_items);
           mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
           mDrawerList = (ListView) findViewById(R.id.left_drawer);

           // 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
           mDrawerList.setAdapter(new ArrayAdapter<String>(this,
                   R.layout.drawer_list_item, mTitles));
           mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

           // enable ActionBar app icon to behave as action to toggle nav drawer
           getActionBar().setDisplayHomeAsUpEnabled(true);
           getActionBar().setHomeButtonEnabled(true);

           // ActionBarDrawerToggle ties together the the proper interactions
           // between the sliding drawer and the action bar app icon
           mDrawerToggle = new ActionBarDrawerToggle(
                   this,                  /* host Activity */
                   mDrawerLayout,         /* DrawerLayout object */
                   R.drawable.ic_drawer,  /* nav drawer image to replace 'Up' caret */
                   R.string.drawer_open,  /* "open drawer" description for accessibility */
                   R.string.drawer_close  /* "close drawer" description for accessibility */
                   ) {
               public void onDrawerClosed(View view) {
                   getActionBar().setTitle(mTitle);
                   invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
               }

               public void onDrawerOpened(View drawerView) {
                   getActionBar().setTitle(mDrawerTitle);
                   invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
               }
           };
           mDrawerLayout.setDrawerListener(mDrawerToggle);

          // if (savedInstanceState == null) {
               selectItem(0);
           }


       @Override
       public boolean onCreateOptionsMenu(Menu menu) {
           MenuInflater inflater = getMenuInflater();
           inflater.inflate(R.menu.main, menu);
           return super.onCreateOptionsMenu(menu);
       }

       /* Called whenever we call invalidateOptionsMenu() */
       @Override
       public boolean onPrepareOptionsMenu(Menu menu) {
           // If the nav drawer is open, hide action items related to the content view
           boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
         //  menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
           return super.onPrepareOptionsMenu(menu);
       }

       @Override
       public boolean onOptionsItemSelected(MenuItem item) {
            // The action bar home/up action should open or close the drawer.
            // ActionBarDrawerToggle will take care of this.
           if (mDrawerToggle.onOptionsItemSelected(item)) {
               return true;
           }
               return super.onOptionsItemSelected(item);       
           }


       /* The click listner for ListView in the navigation drawer */
       private class DrawerItemClickListener implements ListView.OnItemClickListener {
           @Override
           public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
               selectItem(position);
           }
       }

       private void selectItem(int position) {
           switch (position) {
           case 1:
               new DataTask(MainActivity.this).execute();   
               MainActivity.this.finish();//Set this Activity to Finish so no loop back       
               Intent intent=new Intent(MainActivity.this,SplashScreen.class);
               startActivity(intent);
               break;
           case 2:
              // ft.replace(R.id.content_frame, new SecondFragment());
            //  setTitle("Second");
               break;
           case 3:
              // ft.replace(R.id.content_frame, new ThirdFragment());
            //   setTitle("Third");
               break;

           default:
               break;
           }
           // update selected item and title, then close the drawer
           mDrawerList.setItemChecked(position, true);
           //setTitle(mTitles[position]);
           mDrawerLayout.closeDrawer(mDrawerList);
       }

       @Override
       public void setTitle(CharSequence title) {
           mTitle = title;
           getActionBar().setTitle(mTitle);
       }

       /**
        * When using the ActionBarDrawerToggle, you must call it during
        * onPostCreate() and onConfigurationChanged()...
        */

       @Override
       protected void onPostCreate(Bundle savedInstanceState) {
           super.onPostCreate(savedInstanceState);
           // Sync the toggle state after onRestoreInstanceState has occurred.
           mDrawerToggle.syncState();
       }

       @Override
       public void onConfigurationChanged(Configuration newConfig) {
           super.onConfigurationChanged(newConfig);
           // Pass any configuration change to the drawer toggls
           mDrawerToggle.onConfigurationChanged(newConfig);
       }

       /**
        * Fragment that appears in the "content_frame", shows a planet
        */
       public static class PlanetFragment extends Fragment {
           public static final String ARG_PLANET_NUMBER = "planet_number";

           public PlanetFragment() {
               // Empty constructor required for fragment subclasses
           }

         //  @Override
        /*   public View onCreateView(LayoutInflater inflater, ViewGroup container,
                   Bundle savedInstanceState) {
               View rootView = inflater.inflate(R.layout.fragment_planet, container, false);
               int i = getArguments().getInt(ARG_PLANET_NUMBER);
               String planet = getResources().getStringArray(R.array.planets_array)[i];

               int imageId = getResources().getIdentifier(planet.toLowerCase(Locale.getDefault()),
                               "drawable", getActivity().getPackageName());
               ((ImageView) rootView.findViewById(R.id.image)).setImageResource(imageId);
               getActivity().setTitle(planet);
               return rootView;                      */
           }

Wenn Sie Hilfe leisten können, wäre das großartig, da ich mir hier wirklich die Haare ausziehe. Danke.