title: SimpleCursorAdapter on a ViewPager
body: <p>How do I get a ListView using a SimpleCursorAdapter to show in a ViewPager? The Pager alone works just fine and the ListView works ok in a ListActivity, but I dont know how to make it works in an Activity (maybe it's the problem).</p>
  
  <pre><code>public class Player extends Activity {
  private ViewPager pager;
  private static int NUMERO_DE_TELAS = 3;
  private AdaptadorDeTelas adaptador;
  
  //Para debug apagar no final    
  final String BABAS = "babas";
  
  ContentResolver mContentResolver;
  
  ListView listView;
  
  
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
  
      //Adaptador para criar o viewpager
      adaptador = new AdaptadorDeTelas();
      pager = (ViewPager)findViewById(R.id.pageradapter);
      pager.setAdapter(adaptador);        
  
      pager.setCurrentItem(1);       
  
  
  
  
  
  }
  private class AdaptadorDeTelas extends PagerAdapter{
  
      @Override
      public int getCount(){
          return NUMERO_DE_TELAS;
      }
  
      @Override
      public Object instantiateItem(View collection, int position){           
  
  
          View layout;
          LayoutInflater inflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
  
          if(position == 0){
          layout = inflater.inflate(R.layout.layout_zero, null);
          }else if(position == 1){
              layout = inflater.inflate(R.layout.layout_um, null);
          }else{
  
  
              Uri todasMusicas = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
  
              //Seleciona as tabelas a serem retornadas do content audio.media
              String[] projection = {MediaStore.Audio.Media._ID, MediaStore.Audio.Media.TITLE
              };
  
              //Pega todas as músicas no aparelho
              String selection = MediaStore.Audio.Media.IS_MUSIC + " != 0";
  
  
              Cursor cursor;
  
              cursor = Player.this.managedQuery(
                  todasMusicas,
                  projection,
                  selection,
                  null,
                  MediaStore.Audio.Media.TITLE + " ASC");
  
  
  
         String[] from = new String []{MediaStore.Audio.Media.TITLE};
         int[] to = new int[] {R.id.textView1};
  
          View v = (View) findViewById(R.layout.layout_dois);
  
          listView = (ListView) findViewById(R.id.listView1);
          SimpleCursorAdapter meuAdaptador = new SimpleCursorAdapter(Player.this,         R.layout.layout_dois, cursor, from, to);
  
          listView.setAdapter(meuAdaptador);
  
          layout = listView;;
          }
  
  
  
          ((ViewPager)collection).addView((View) layout, 0);                   
  
          return layout;
  
  
      }
  
  
      @Override
      public void destroyItem(View collection, int position, Object view){
          ((ViewPager) collection).removeView((View)view);
  
      }
  
      @Override
      public boolean isViewFromObject(View view, Object object){
          return view==((View)object);
      }
  
      @Override
      public void finishUpdate(View arg0){}
  
      @Override
      public void restoreState(Parcelable arg0, ClassLoader arg1){}
  
      @Override
      public Parcelable saveState(){
          return null;
      }
  
      @Override
      public void startUpdate(View arg0){}
  
  
  }
  </code></pre>
  
  <p>I'm trying to show a list of the musics in the sd card in one of the pages of the ViewPager, thanks in advance for anyone who helpme out. </p>
  
  <p>Ps: Sorry for the bad english and for the portuguese in the comments in the code.</p>
  
  <p>This is the error that shows in the LogCat:</p>
  
  <pre><code>01-15 16:48:41.623: W/dalvikvm(270): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
  01-15 16:48:41.653: E/AndroidRuntime(270): FATAL EXCEPTION: main
  01-15 16:48:41.653: E/AndroidRuntime(270): java.lang.NullPointerException
  01-15 16:48:41.653: E/AndroidRuntime(270):  at br.com.babas.player.Player$AdaptadorDeTelas.instantiateItem(Player.java:113)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:321)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.support.v4.view.ViewPager.populate(ViewPager.java:441)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.support.v4.view.ViewPager.onAttachedToWindow(ViewPager.java:563)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.view.View.dispatchAttachedToWindow(View.java:6016)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:1116)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:1121)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:1121)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:1121)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:1121)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.view.ViewRoot.performTraversals(ViewRoot.java:727)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1727)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.os.Handler.dispatchMessage(Handler.java:99)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.os.Looper.loop(Looper.java:123)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at android.app.ActivityThread.main(ActivityThread.java:4627)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at java.lang.reflect.Method.invokeNative(Native Method)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at java.lang.reflect.Method.invoke(Method.java:521)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
  01-15 16:48:41.653: E/AndroidRuntime(270):  at dalvik.system.NativeStart.main(Native Method)
  </code></pre>