我已经测试了这个code。在我的手机，它是工作

I have tested this code in my mobile and it is working

AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
        int sb2value = audioManager.getStreamMaxVolume(AudioManager.STREAM_RING);
        NotificationManager notificationManager = (NotificationManager) getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE);
        Notification notification = new Notification(R.drawable.ic_launcher, "Testomg", System.currentTimeMillis() + 5000);

        Intent notificationIntent = new Intent(Intent.ACTION_VIEW);
        notificationIntent.setData(Uri.parse("market://details?id=com.karya.kot"));
        notificationIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        PendingIntent intent = PendingIntent.getActivity(getApplicationContext(), 0, notificationIntent, 0);
        notification.setLatestEventInfo(getApplicationContext(), "Google Play", "Download app", intent);

        notification.flags |= Notification.FLAG_AUTO_CANCEL;
        notificationManager.notify(0, notification);