Android Service binding with MvvmCross - xamarin

Question

I am developing xamarin.Android app in MvvmCross. I want to call a service even when the App is backgrounded and a user is logged in. The problem is, I want to call this service within every say 2 hours whether the app is in foreground or background, just the user of the App needs to be logged in.
Intent loggedintent = new Intent(this,typeof(DeviceLoginHelper));
loggedintent.PutExtra("LoggedIn", true);
StartService(loggedintent);
I have written an android service:
[Service]
public class DeviceLoginHelper : IntentService
{
protected override void OnHandleIntent(Intent intent)
{
try
{
if(intent.HasExtra("LoggedIn"))
{
}
}
catch(Exception ex) { }
}
}
But how can I implement a timer? Where do I initialise and handle event to the timer. And when timer is elapsed when should I call ?
public override void OnDestroy()
{
try
{
base.OnDestroy();
}
catch(Exception ex){}
}
and when a user loges out i want to stop this service. Where do I put the call StopService() in MvvmCross

Answer 1

I would not use a Timer. Instead you should configure the AlarmManager.
[BroadcastReceiver]
public class AlarmReceiver : BroadcastReceiver
{
private static AlarmManager alarmMgr;
private static PendingIntent alarmIntent;
public const int NOTIFICATION_ID = 1;
public const int IDLE_TIME_MS = 30 * 1000; // 30-seconds (update here)
private NotificationManager mNotificationManager;
Notification.Builder builder;
public override void OnReceive(Context context, Intent intent)
{
// Do something when alarm triggers (here I'm building notification)
BuildNotification(context);
// reschedule alarm
ScheduleAlarm(IDLE_TIME_MS);
}
public static Context ApplicationContext { get; set; }
public static void ScheduleAlarm(int milliseconds)
{
if (milliseconds == 0) return;
alarmMgr = (AlarmManager)ApplicationContext.GetSystemService(Context.AlarmService);
var intent = new Intent(ApplicationContext, typeof(AlarmReceiver));
alarmIntent = PendingIntent.GetBroadcast(ApplicationContext, 0, intent, 0);
alarmMgr.Set(AlarmType.ElapsedRealtimeWakeup,
SystemClock.ElapsedRealtime() + milliseconds, alarmIntent);
}
private void BuildNotification(Context context)
{
mNotificationManager = (NotificationManager)context.GetSystemService(Context.NotificationService);
var contentIntent = PendingIntent.GetActivity(context, 0, new Intent(context, typeof(MainView)), 0);
var message = $"Time is up";
var mBuilder = new Notification.Builder(context)
.SetAutoCancel(true)
.SetPriority(NotificationCompat.PriorityMax)
.SetDefaults(NotificationDefaults.All)
.SetContentTitle("Time is up")
.SetStyle(new Notification.BigTextStyle()
.BigText(message))
.SetContentText(message)
.SetSmallIcon(Resource.Drawable.ic_launcher);
mBuilder.SetContentIntent(contentIntent);
mNotificationManager.Notify(NOTIFICATION_ID, mBuilder.Build());
}
}
In your startup code, simply call:
AlarmReceiver.ApplicationContext = context;
AlarmReceiver.ScheduleAlarm(timeInMs);