Android Notifications Scheduling notifications
Example
Sometimes it is required to display a notification at a specific time, a task that unfortunately is not trivial on the Android system, as there is no method setTime() or similiar for notifications. This example outlines the steps needed to schedule notifications using the AlarmManager:
- Add a
BroadcastReceiverthat listens toIntents broadcasted by the AndroidAlarmManager.
This is the place where you build your notification based on the extras provided with the Intent:
public class NotificationReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
// Build notification based on Intent
Notification notification = new NotificationCompat.Builder(context)
.setSmallIcon(R.drawable.ic_notification_small_icon)
.setContentTitle(intent.getStringExtra("title", ""))
.setContentText(intent.getStringExtra("text", ""))
.build();
// Show notification
NotificationManager manager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
manager.notify(42, notification);
}
}
-
Register the
BroadcastReceiverin yourAndroidManifest.xmlfile (otherwise the receiver won't receive anyIntents from theAlarmManager):<receiver android:name=".NotificationReceiver" android:enabled="true" /> -
Schedule a notification by passing a
PendingIntentfor yourBroadcastReceiverwith the neededIntentextras to the systemAlarmManager. YourBroadcastReceiverwill receive theIntentonce the given time has arrived and display the notification. The following method schedules a notification:public static void scheduleNotification(Context context, long time, String title, String text) { Intent intent = new Intent(context, NotificationReceiver.class); intent.putExtra("title", title); intent.putExtra("text", text); PendingIntent pending = PendingIntent.getBroadcast(context, 42, intent, PendingIntent.FLAG_UPDATE_CURRENT); // Schdedule notification AlarmManager manager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE); manager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, time, pending); }Please note that the
42above needs to be unique for each scheduled notification, otherwise thePendingIntents will replace each other causing undesired effects! -
Cancel a notification by rebuilding the associated
PendingIntentand canceling it on the systemAlarmManager. The following method cancels a notification:public static void cancelNotification(Context context, String title, String text) { Intent intent = new Intent(context, NotificationReceiver.class); intent.putExtra("title", title); intent.putExtra("text", text); PendingIntent pending = PendingIntent.getBroadcast(context, 42, intent, PendingIntent.FLAG_UPDATE_CURRENT); // Cancel notification AlarmManager manager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE); manager.cancel(pending); }
Note that the 42 above needs to match the number from step 3!
