Android development tutorial listview displays sqlite data

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public class MainActivity extends Activity {
 private ListView lv;
 private List<Person> persons;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  (savedInstanceState);
  setContentView(.activity_main);

  PersonDao dao=new PersonDao(this);
  persons=();
  lv=(ListView) findViewById();
  (new MyAdapter());

  (new OnItemClickListener() {
//Clicked data to the previous activity
   @Override
   public void onItemClick(AdapterView<?> parent, View view,
     int position, long id) {
    // TODO Auto-generated method stub
    Person mperson=(position);
    String number=();
    Intent data=new Intent();
    ("number", number);
    setResult(0, data);
//Click to close this activity
    finish();
   }
  });
 }

 private class MyAdapter extends BaseAdapter{
  private static final String TAG = "MyAdapter";

  /**
* Control how many entries are in the listview
   */
  @Override
  public int getCount() {
   // TODO Auto-generated method stub
   return ();
  }

  @Override
  public Object getItem(int position) {
   // TODO Auto-generated method stub
   return null;
  }

  @Override
  public long getItemId(int position) {
   // TODO Auto-generated method stub
   return 0;
  }

  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
   // TODO Auto-generated method stub
   /**
* Use inflater to display
    */
   Person person=(position);
   View view=(, .list_item, null);

   TextView tv_id=(TextView) (.tv_id);
   tv_id.setText("id:"+());

   TextView tv_name=(TextView) (.tv_name);
tv_name.setText("name:"+());

   TextView tv_number=(TextView) (.tv_number);
tv_number.setText("Tel:"+());

   return view;
   }
   /**
* No inflater
    *
(tag, "position"+position);   //See the effect
   TextView tv=new TextView(getApplicationContext());
   (20);
   ();
//Entries on each location
   Person person=(position);
   (());
   return tv;
  }*/

 }
}