Android Notification NullPointer

I want to create a notification and I have this bit of code that worked before but now gives me a null pointer at the last line.

Any ideas as to what may cause this?

I know it may be hard with this bit of code that I have provided, I just need a hint as to what could possibly cause this.

   private void showNotification() {

    CharSequence text = getText(R.string.myString);开发者_StackOverflow社区


    Notification notification = new Notification(R.drawable.playbackstart, text,
            System.currentTimeMillis());


    PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
            new Intent(this, MyActivity.class), 0);


    notification.setLatestEventInfo(this, getText(R.string.myString),
                   text, contentIntent);



    mNM.notify(R.string.myString, notification);
}

I was getting a NullPointerException when I called (NotificationManager)getSystemService(NOTIFICATION_SERVICE); from within the constructor.

I had to move the call to get the NotificationManager to the onStart call.

@Override
public void onStart(Intent intent, int startId) {
    try {
        notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    } catch (Exception e) {
        Log.e(TAG, e.toString());
    }
    super.onStart(intent, startId);
}

mNM is null, since R.string.myString must exist otherwise it won't compile, and notification is used before, therefore cannot be null, otherwise would gotten a NPE earlier. Therefore, check mNM. Or post the entire code where mNM is initialized.

Instead of using

mNM = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);

you should prefix the NOTIFICATION_SERVICE with Context, which looks like :

mNM = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);

If you look into the documentation of the class Context, you can find that the value of the "static final String NOTIFICATION_SERVICE" is "notification", but not NOTIFICATION_SERVICE.

So it is normal that you get a NullpointerException when only using NOTIFICATION_SERVICE.