Google Android - это несложно

Код: Выделить всё

public class ListViewLoader extends ListActivity
implements LoaderManager.LoaderCallbacks<Cursor> {



// This is the Adapter being used to display the list's data
SimpleCursorAdapter mAdapter;

// These are the Contacts rows that we will retrieve

static final String] PROJECTION = new String] {ContactsContract.Groups._ID,
ContactsContract.Groups.TITLE};

// This is the select criteria
static final String SELECTION = "((" + 
ContactsContract.Groups.TITLE + " NOTNULL) AND (" +
ContactsContract.Groups.TITLE + " != '' ))";

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

// Create a progress bar to display while the list loads
ProgressBar progressBar = new ProgressBar(this);
progressBar.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT, Gravity.CENTER));
progressBar.setIndeterminate(true);
getListView().setEmptyView(progressBar);

// Must add the progress bar to the root of the layout
ViewGroup root = (ViewGroup) findViewById(android.R.id.content);
root.addView(progressBar);

// For the cursor adapter, specify which columns go into which views
String] fromColumns = {ContactsContract.Groups.TITLE};
int] toViews = {android.R.id.text1}; // The TextView in simple_list_item_1

// Create an empty adapter we will use to display the loaded data.
// We pass null for the cursor, then update it in onLoadFinished()
mAdapter = new SimpleCursorAdapter(this, 
android.R.layout.simple_list_item_1, null,
fromColumns, toViews, 0);
setListAdapter(mAdapter);

// Prepare the loader. Either re-connect with an existing one,
// or start a new one.
getLoaderManager().initLoader(0, null, this);
}

// Called when a new Loader needs to be created
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
// Now create and return a CursorLoader that will take care of
// creating a Cursor for the data being displayed.
return new CursorLoader(this, ContactsContract.Groups.CONTENT_SUMMARY_URI,
PROJECTION, SELECTION, null, null);
}

// Called when a previously created loader has finished loading
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.)
mAdapter.swapCursor(data);
}

// Called when a previously created loader is reset, making the data unavailable
public void onLoaderReset(Loader<Cursor> loader) {
// This is called when the last Cursor provided to onLoadFinished()
// above is about to be closed. We need to make sure we are no
// longer using it.
mAdapter.swapCursor(null);