Detailed explanation and examples of Android onLoadFinished and onLoaderReset callbacks

//This Adapter is used to display the data of the list.SimpleCursorAdapter mAdapter; 
... 
 
public void onLoadFinished(Loader<Cursor> loader, Cursor data) { 
  // Swap the new cursor in. (The framework will take care of closing the 
  // old cursor once we return.) 
  (data); 
} 

// This Adapter is used to display the data of the listSimpleCursorAdapter mAdapter;
... 
 
public void onLoaderReset(Loader<Cursor> loader) { 
  //Here is the cursor used for the above onLoadFinished() will be executed when it is closed, we need to make sure we no longer use it  (null); 
}

public static class CursorLoaderListFragment extends ListFragment 
    implements OnQueryTextListener, <Cursor> { 
 
  // This is the Adapter for displaying list data  SimpleCursorAdapter mAdapter; 
 
  // If not null, this is the current search oversight  String mCurFilter; 
 
  @Override public void onActivityCreated(Bundle savedInstanceState) { 
    (savedInstanceState); 
 
    // If there is no data in the list, give the control some text to display.  In a real application    // Get this application resource.    setEmptyText("No phone numbers"); 
 
    // We have a menu item in the action bar.    setHasOptionsMenu(true); 
 
    // Create an empty adapter, we will use it to display the loaded data    mAdapter = new SimpleCursorAdapter(getActivity(), 
        .simple_list_item_2, null, 
        new String[] { Contacts.DISPLAY_NAME, Contacts.CONTACT_STATUS }, 
        new int[] { .text1, .text2 }, 0); 
    setListAdapter(mAdapter); 
 
    // Prepare loader. Maybe reconnect to an existing one or start a new one    getLoaderManager().initLoader(0, null, this); 
  } 
 
  @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { 
    // Place an action bar item for searching.    MenuItem item = ("Search"); 
    (.ic_menu_search); 
    (MenuItem.SHOW_AS_ACTION_IF_ROOM); 
    SearchView sv = new SearchView(getActivity()); 
    (this); 
    (sv); 
  } 
 
  public boolean onQueryTextChange(String newText) { 
    // Called when the search string on the action bar changes.  renew    //Search the filter and restart the loader to execute a new query    mCurFilter = !(newText) ? newText : null; 
    getLoaderManager().restartLoader(0, null, this); 
    return true; 
  } 
 
  @Override public boolean onQueryTextSubmit(String query) { 
    // We don't care about this method    return true; 
  } 
 
  @Override public void onListItemClick(ListView l, View v, int position, long id) { 
    // Write the code you want to write    ("FragmentComplexList", "Item clicked: " + id); 
  } 
 
  // This is the data from a row of contacts we want to obtain.  static final String[] CONTACTS_SUMMARY_PROJECTION = new String[] { 
    Contacts._ID, 
    Contacts.DISPLAY_NAME, 
    Contacts.CONTACT_STATUS, 
    Contacts.CONTACT_PRESENCE, 
    Contacts.PHOTO_ID, 
    Contacts.LOOKUP_KEY, 
  }; 
  public Loader<Cursor> onCreateLoader(int id, Bundle args) { 
    // Called when a new loader needs to be created.  There is only one Loader in this case.    //So we don’t need to care about ID.  First set the base URI, which points to the contact person    Uri baseUri; 
    if (mCurFilter != null) { 
      baseUri = (Contacts.CONTENT_FILTER_URI, 
          (mCurFilter)); 
    } else { 
      baseUri = Contacts.CONTENT_URI; 
    } 
 
    // Now create and return a CursorLoader, which will be responsible for creating a    // Cursor is used to display data    String select = "((" + Contacts.DISPLAY_NAME + " NOTNULL) AND (" 
        + Contacts.HAS_PHONE_NUMBER + "=1) AND (" 
        + Contacts.DISPLAY_NAME + " != '' ))"; 
    return new CursorLoader(getActivity(), baseUri, 
        CONTACTS_SUMMARY_PROJECTION, select, null, 
        Contacts.DISPLAY_NAME + " COLLATE LOCALIZED ASC"); 
  } 
 
  public void onLoadFinished(Loader<Cursor> loader, Cursor data) { 
    // Swap the new cursor in.  (The framework will care about the closing of the old cursor when we return)    (data); 
  } 
 
  public void onLoaderReset(Loader<Cursor> loader) { 
    //Before the last Cursor is ready to enter the above onLoadFinished().    // Cursor is going to be closed, we need to make sure it is no longer used.    (null); 
  } 
}