NotificationListenerService不显示任何内容

Question

我找到了这个很棒的教程：http://gmariotti.blogspot.it/search?q=NotificationListenerService我尝试下载源代码并将其用于我的应用程序以阅读whatsapp通知但我看不到任何内容..它看起来很简单但不起作用为了我。 NotificationListenerService：

public class SimpleKitkatNotificationListener extends NotificationListenerService {

    @Override
    public void onCreate() {
        super.onCreate();
        //android.os.Debug.waitForDebugger();
    }

    @Override
    public void onNotificationPosted(StatusBarNotification sbn) {
        Notification mNotification=sbn.getNotification();
        if (mNotification!=null){
            Bundle extras = mNotification.extras;

            Intent intent = new Intent(MainActivity.INTENT_ACTION_NOTIFICATION);
            intent.putExtras(mNotification.extras);
            sendBroadcast(intent);

            Notification.Action[] mActions=mNotification.actions;
            if (mActions!=null){
                for (Notification.Action mAction:mActions){
                    int icon=mAction.icon;
                    CharSequence actionTitle=mAction.title;
                    PendingIntent pendingIntent=mAction.actionIntent;
                }
            }
        }
    }

    @Override
    public void onNotificationRemoved(StatusBarNotification sbn) {

    }
}

和活动：

public class MainActivity extends Activity {

    protected MyReceiver mReceiver = new MyReceiver();
    public static String INTENT_ACTION_NOTIFICATION = "it.gmariotti.notification";

    protected TextView title;
    protected TextView text;
    protected TextView subtext;
    protected ImageView largeIcon;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //Retrieve ui elements
        title = (TextView) findViewById(R.id.nt_title);
        text = (TextView) findViewById(R.id.nt_text);
        subtext = (TextView) findViewById(R.id.nt_subtext);
        largeIcon = (ImageView) findViewById(R.id.nt_largeicon);

    }

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

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.action_autorize:
                Intent intent = new Intent("android.settings.ACTION_NOTIFICATION_LISTENER_SETTINGS");
                startActivity(intent);
                return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onResume() {
        super.onResume();
        if (mReceiver == null) mReceiver = new MyReceiver();
        registerReceiver(mReceiver, new IntentFilter(INTENT_ACTION_NOTIFICATION));
    }

    @Override
    protected void onPause() {
        super.onPause();
        unregisterReceiver(mReceiver);
    }

    public class MyReceiver extends BroadcastReceiver {

        @Override
        public void onReceive(Context context, Intent intent) {

            if (intent != null) {
                Bundle extras = intent.getExtras();
                String notificationTitle = extras.getString(Notification.EXTRA_TITLE);
                int notificationIcon = extras.getInt(Notification.EXTRA_SMALL_ICON);
                Bitmap notificationLargeIcon = ((Bitmap) extras.getParcelable(Notification.EXTRA_LARGE_ICON));
                CharSequence notificationText = extras.getCharSequence(Notification.EXTRA_TEXT);
                CharSequence notificationSubText = extras.getCharSequence(Notification.EXTRA_SUB_TEXT);

                title.setText(notificationTitle);
                text.setText(notificationText);
                subtext.setText(notificationSubText);

                if (notificationLargeIcon != null) {
                    largeIcon.setImageBitmap(notificationLargeIcon);
                }
            }

        }
    }
}

是的，我已经自动化了应用程序以阅读通知。我用CM11获得了Android 4.4.2 ..我不知道这是不是问题。