Question

I’ve got an application that needs to show a notification of certain events in a day, depending on the event.

I know how to do it, if I need a service to stay running in the background, or it will run in the background getting these events on certain days.

private void Notificar(String descricaoEvento){
    NotificationManager notifier = (NotificationManager)this.getSystemService(Context.NOTIFICATION_SERVICE);
    Notification notification = new Notification(R.drawable.ic_launcher, "Novo evento no The Point Club", System.currentTimeMillis()); 
    notification.flags |= Notification.DEFAULT_SOUND;

    PendingIntent pIntent = PendingIntent.getActivity(this, 0, null, 0); 
    notification.setLatestEventInfo(this, "Title", descricaoEvento.toString(), pIntent);        
    notifier.notify(0x007, notification);       
}

using this method to call when the right date!

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Thanks for listening, I’ll try to explain what I’m doing right: I’m making an application for a club party, and the application will show the next event of the celebrations when I open the application, but what I wish is that a notification is created in android notification bar, on which there is a party, serving as a reminder.

I use this code when I open the activity to list events:

    Calendar c = Calendar.getInstance();
    c.setTimeInMillis(System.currentTimeMillis());
    int anoAtual= c.get(Calendar.YEAR);
    long time = c.getTimeInMillis();
    Intent it = new Intent("EXECUTAR_ALARME") 
    p = PendingIntent.getBroadcast(Eventos.this, 0, it, 0);
    AlarmManager alarme = (AlarmManager) getSystemService(ALARM_SERVICE);
    alarme.set(AlarmManager.RTC_WAKEUP, time, p);

the line

    Intent it = new Intent("EXECUTAR_ALARME") 

will call the class:

    public class Alarm extends BroadcastReceiver{   @Override
       public void onReceive(Context contexto, Intent intent) {
           NotificationManager notifier =(NotificationManager) contexto.getSystemService(Context.NOTIFICATION_SERVICE);
           Notification notification = new Notification(R.drawable.ic_launcher, "New event in Club", System.currentTimeMillis()); 
           notification.flags |= Notification.DEFAULT_SOUND;
           //Intent i = new Intent(this, Eventos.class);
           PendingIntent pIntent = PendingIntent.getActivity(contexto, 0, null, 0); 
           notification.setLatestEventInfo(contexto, "Club", "Teste", pIntent);     
           notifier.notify(0x007, notification);  


       }

}

Now I want to know two things:
1 – How do I leave it running in the background without being open with the application.
2 This code only creates only an alarm, and I need to create multiple.

Thanks for the help.

Answer 1

Use AlarmManager to run a PendingIntent at your specific time. At that time, the intent that it stored in the PendingIntent should likely be a service if you’re planning on creating a Notification to display to the user. If you could form this as a question, I may be able to help more, but it’s unclear what you’re trying to accomplish, and what you’ve managed to accomplish.

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Additional Details

In your code, it looks like you’re scheduling the alarm for right now, instead of at some time in the future. I’d suggest the following to create the alarm:

    Calendar c = Calendar.getInstance();
    // don't do this:
    // c.setTimeInMillis(System.currentTimeMillis()); // This just sets the alarm time to "now"

    // set the calendar to 8:00 pm:
    c.set(Calendar.HOUR_OF_DAY, 20);
    c.set(Calendar.MINUTE, 0);

    long alarmTime = c.getTimeInMillis();
    Intent it = new Intent(ServiceClass.getClass());
    // Even though the docs say that the request code doesn't matter making it unique tells the alarmManager that it's a different PendingIntent
    PendingIntent pendingIntent = PendingIntent.getService(this, 0, it, 0);

    AlarmManager alarmMgr = (AlarmManager) getSystemService(ALARM_SERVICE);
    alarmMgr.set(AlarmManager.RTC_WAKEUP, alarmTime, pendingIntent); // set the first alarm for 8:00

    c.set(Calendar.MINUTE, 30);
    Intent it2 = new Intnt(ServiceClass.getClass());
    PendingIntent pi2 = PendingIntent.getService(this, 0, it2, 0);
    alarmMgr.set(AlarmManager.RTC_WAKEUP, alarmTime, pi2); // set the second alarm for 8:30

the line

Intent it = new Intent(ServiceClass.getClass());

will start the Class ServiceClass:

class ServiceClass extends Service {

    @Override
    public IBinder onBind(Intent intent) {
        // TODO TRAVIS Auto-generated method stub
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) { // onStartCommand is run when the service is started by the AlarmManager
        // build and set the notification here
        NotificationManager notifMgr = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        // build notification
        Notification notification = new Notification.Builder(getApplicationContext())
                .setContentTitle("New mail from " + sender.toString())
                .setContentText(subject)
                .setSmallIcon(R.drawable.new_mail)
                .setLargeIcon(aBitmap)
                .build();

        int ID = 0;

        notifMgr.notify(ID++, notification);   // use a unique id every time if you want multiple notifications (sounds like what you want, but not a best practice)

        notification = new Notification.Builder(getApplicationContext())
                .setContentTitle("New event from " + sender.toString())
                .setContentText(subject)
                .setSmallIcon(R.drawable.new_mail)
                .setLargeIcon(aBitmap)
                .build();

        notifMgr.notify(ID++, notification);  // add the second notification to the notification bar            
        return super.onStartCommand(intent, flags, startId);
    }
}

Answers to your questions:

1 – By setting the alarm for sometime in the future, you’re asking the OS to start your PendingIntent (in your case, send a Broadcast; in my exmaple above, a Service) at the time specified (that’s why you need to set the time with the calendar to sometime in the future!)

2 – Creating multiple alarms is a matter of calling the alarm manager with different PendingIntent s scheduled at the appropriate time (for when you want them to fire). The same is true for Notification s, create multiple ones (with unique ids).