Xamarin Android - How to schedule and alarm with a BroadcastReceiver - xamarin

Question

(I'm asking here because I didn't get help at Xamarin forums) I'm creating an alarm with this code:
Intent alarmIntent = new Intent(context, typeof(AlarmReceiver));
notificationClickIntent = PendingIntent.GetActivity(context, 0, new Intent(), 0);
pendingIntent = PendingIntent.GetBroadcast(context, 0, alarmIntent, PendingIntentFlags.UpdateCurrent);
am = (AlarmManager)Android.App.Application.Context.GetSystemService(Context.AlarmService);
DateTime setTime = new DateTime(temp.Ticks + offset); //temp is the current time where seconds field = 0
if ((int)Build.VERSION.SdkInt >= 21) //my device enters this case
{
AlarmManager.AlarmClockInfo info = new AlarmManager.AlarmClockInfo(setTime.Ticks, notificationClickIntent);
am.SetAlarmClock(info, pendingIntent);
}
else {
am.SetExact(AlarmType.RtcWakeup, setTime.Ticks, notificationClickIntent);
}
Before that code is called, my class makes sure that these have also been executed:
ComponentName receiver = new ComponentName(context, Java.Lang.Class.FromType(typeof(AlarmReceiver)));
PackageManager pm = context.PackageManager;
pm.SetComponentEnabledSetting(receiver, ComponentEnabledState.Enabled, ComponentEnableOption.DontKillApp);
Intent alarmIntent = new Intent(context, typeof(AlarmReceiver));
notificationClickIntent = PendingIntent.GetActivity(context, 0, new Intent(), 0);
pendingIntent = PendingIntent.GetBroadcast(context, 0, alarmIntent, PendingIntentFlags.UpdateCurrent);
am = (AlarmManager)Android.App.Application.Context.GetSystemService(Context.AlarmService);
And here is my receiver:
[BroadcastReceiver (Process = ":remote")]
public class AlarmReceiver : BroadcastReceiver
{
public override void OnReceive(Context context, Intent intent)
{
Console.WriteLine("alarm fired");
Toast.MakeText(context, "Received intent!", ToastLength.Short).Show();
}
}
Okay, so the receiver is being registered by Xamarin correctly. I know this because if I give an incorrect tick value to AlarmClockInfo (a value outside of DateTime's tick range) the alarm goes off immediately and my OnReceive method is called. However when I give it a tick value, say a minute ahead of the current time, the alarm doesn't go off. Maybe the time is wrong?... Doesn't seem so because I have logged the time of the the system's next scheduled alarm and it reports back with the same time I set it for. Any thoughts?
EDIT: So I already have an android app that performs all this correctly. When I convert it to Xamarin and C#, it no longer works.

Answer 1

This is how I'm creating a local notification in my Xamarin app.
DateTime time = ... // whatever time
AlarmManager manager = (AlarmManager)context.GetSystemService(Context.AlarmService);
Java.Util.Calendar calendar = Java.Util.Calendar.Instance;
calendar.TimeInMillis = Java.Lang.JavaSystem.CurrentTimeMillis();
calendar.Set(time.Year, time.Month - 1, time.Day, time.Hour, time.Minute, 0);
manager.SetRepeating(AlarmType.RtcWakeup, calendar.TimeInMillis,
AlarmManager.IntervalDay, pendingIntent);
And here is the BroadcastReceiver class:
[BroadcastReceiver]
public class AlarmReceiver : BroadcastReceiver
{
public override void OnReceive(Context context, Intent intent)
{
NotificationManager nManager = (NotificationManager)context.GetSystemService(Context.NotificationService);
Intent repeatingIntent;
// Here I'm opening two different Activities based on condition
if (CommonUtils.isLoggedIn()))
{
repeatingIntent = new Intent(context, typeof(MainActivity));
repeatingIntent.PutExtra(MainActivity.SELECT_TAB, 1);
}
else
{
repeatingIntent = new Intent(context, typeof(SplashActivity));
}
repeatingIntent.SetFlags(ActivityFlags.ClearTop);
PendingIntent pIntent = PendingIntent.GetActivity(context, 100, repeatingIntent, PendingIntentFlags.UpdateCurrent);
NotificationCompat.Builder builder = new NotificationCompat.Builder(context)
.SetContentIntent(pIntent)
.SetSmallIcon(Resource.Drawable.az_logo_small)
.SetColor(ContextCompat.GetColor(context, Resource.Color.PrimaryColor))
.SetContentTitle(CommonUtils.MAIN_TITLE)
.SetContentText(UIMessages.VITAL_REMINDER)
.SetAutoCancel(true);
nManager.Notify(100, builder.Build());
}
}
and in AndroidManifest.xml, you need this permission
<uses-permission android:name="com.android.alarm.permission.SET_ALARM" />
also need the register the BroadcastReceiver in AndroidManifest.xml
<application android:label="YourAppName" android:largeHeap="true" android:icon="#drawable/ic_launcher">
<receiver android:name=".AlarmReceiver"></receiver>
</application>
Hope it helps.

Answer 2

First you have to Declare <receiver android:name=".AlarmReceiver"></receiver> in your Manifest inside yout app
And create a BroadcastReceiver class:
[BroadcastReceiver]
class AlarmReceiver : BroadcastReceiver
{
public override void OnReceive(Context context, Intent intent)
{
//Miramos si la alarma debe repetirse
var repeat = intent.GetStringExtra("repeat");
//Hacemos sonar la alarma
Uri notification = RingtoneManager.GetDefaultUri(RingtoneType.Alarm);
Ringtone r = RingtoneManager.GetRingtone(context, notification);
r.Play();
//
}
The following code is to Start and cancel the pending intent
public void SetAlarm(long miliseconds)
{
AlarmManager alarmManager = (AlarmManager)this.Activity.GetSystemService(Context.AlarmService);
Intent intent = new Intent(this.Activity, typeof(AlarmReceiver));
intent.PutExtra("repeat", repeat);
PendingIntent pendingIntent = PendingIntent.GetBroadcast(this.Activity, /*id de la alarma que sea unico */0, intent, PendingIntentFlags.CancelCurrent);
alarmManager.Set(AlarmType.RtcWakeup, miliseconds, pendingIntent);
Toast toast = Toast.MakeText(this.Activity, Resource.String.set_alarm, ToastLength.Short);
toast.Show();
}
public void CancelAlarm()
{
AlarmManager alarmManager = (AlarmManager)this.Activity.GetSystemService(Context.AlarmService);
Intent intent = new Intent(this.Activity, typeof(AlarmReceiver));
PendingIntent pendingIntent = PendingIntent.GetBroadcast(this.Activity, /*a traves del anterior id ahora podemos pedir que se actualice */0, intent, PendingIntentFlags.UpdateCurrent);
//Con el pending intent actualizado podemos cancelarlo
pendingIntent.Cancel();
alarmManager.Cancel(pendingIntent);
Toast toast = Toast.MakeText(this.Activity, Resource.String.remove_alarm, ToastLength.Short);
toast.Show();
}
To finish you have to call them for example when clicking them
if (alarm.Active == true)
{
alarm.Active = false;
alarmsFragment.CancelAlarm();
}
else
{
alarm.Active = true;
// the time you want in milliseconds
long miliseconds = Java.Lang.JavaSystem.CurrentTimeMillis() + 10000 ;
alarmsFragment.SetAlarm(miliseconds);
}