Develop Reference

How to create a foreground service with notification for Android below Oreo 8.0?

I have created a foreground service using the following code which is in the override method OnStartCommand inside a service class called DemoIntentService.cs.
base.OnStartCommand(intent,flags,startId);
if (Build.VERSION.SdkInt >= BuildVersionCodes.O)
{
Intent notificationIntent = new Intent(this, Java.Lang.Class.FromType(typeof(DemoIntentService)));
PendingIntent pendingIntent = PendingIntent.GetActivity(this, 0, notificationIntent, 0);
Notification.Builder notificationBuilder = new Notification.Builder(this, "Example_Service_Channel")
.SetSmallIcon(Resource.Drawable.AlertLightFrame)
.SetContentTitle(Resources.GetString(Resource.String.DialogAlertTitle))
.SetContentText(Resources.GetString(Resource.String.SelectTextMode))
.SetContentIntent(pendingIntent);
Notification notificationAfterBuild = notificationBuilder.Build();
StartForeground(123, notificationAfterBuild);
InitializeAlarmManager();
setAlarm();
}
return StartCommandResult.RedeliverIntent;
Obviously, the code above is only for Android Oreo 8.0 and above, the service works fine and the notification will not be cleared even though I close the app manually. (That's good, that's what I want !). However, when I use the above code to test on Android Nougat 7.1.1, it would not work.
Firstly, I have researched online they said there is no need to create a notification channel for Android below 8.0, so I remove the "Example_Service_Channel" which is the channelID. The app was deployed successfully, but the notification gone when I kill the app. Second thing, when I removed the channelID, Xamarin throw me a warning said "Notification.Builder.Builder(Context) is obsolete : deprecated" and the line has turn yellow. I ignore the error and deploy the app. The service did run as it is visible in the running service inside the developer options. But when I killed the app, the service and notification gone together. Is there any other way to create a foreground notification service that will never end for Android below 8.0? Thanks for any comment and idea.

i write a simple sample,and it works on Android 7.1. i just delete the Notification Channel from Android 8.0
1.Create a Service MyService.cs :
[Service(Enabled = true)]
public class MyService : Service
{
private Handler handler;
private Action runnable;
private bool isStarted;
private int DELAY_BETWEEN_LOG_MESSAGES = 5000;
private int NOTIFICATION_SERVICE_ID = 1001;
private int NOTIFICATION_AlARM_ID = 1002;
public override void OnCreate()
{
base.OnCreate();
handler = new Handler();
//here is what you want to do always, i just want to push a notification every 5 seconds here
runnable = new Action(() =>
{
if (isStarted)
{
DispatchNotificationThatAlarmIsGenerated("I'm running");
handler.PostDelayed(runnable, DELAY_BETWEEN_LOG_MESSAGES);
}
});
}
public override StartCommandResult OnStartCommand(Intent intent, StartCommandFlags flags, int startId)
{
if (isStarted)
{
// service is already started
}
else
{
DispatchNotificationThatServiceIsRunning();
handler.PostDelayed(runnable, DELAY_BETWEEN_LOG_MESSAGES);
isStarted = true;
}
return StartCommandResult.Sticky;
}
public override void OnTaskRemoved(Intent rootIntent)
{
//base.OnTaskRemoved(rootIntent);
}
public override IBinder OnBind(Intent intent)
{
// Return null because this is a pure started service. A hybrid service would return a binder that would
// allow access to the GetFormattedStamp() method.
return null;
}
public override void OnDestroy()
{
// Stop the handler.
handler.RemoveCallbacks(runnable);
// Remove the notification from the status bar.
var notificationManager = (NotificationManager)GetSystemService(NotificationService);
notificationManager.Cancel(NOTIFICATION_SERVICE_ID);
isStarted = false;
base.OnDestroy();
}
//start a foreground notification to keep alive
private void DispatchNotificationThatServiceIsRunning()
{
NotificationCompat.Builder builder = new NotificationCompat.Builder(this)
.SetDefaults((int)NotificationDefaults.All)
.SetSmallIcon(Resource.Drawable.Icon)
.SetVibrate(new long[] { 100, 200, 300, 400, 500, 400, 300, 200, 400 })
.SetSound(null)
.SetPriority(NotificationCompat.PriorityDefault)
.SetAutoCancel(false)
.SetContentTitle("Mobile")
.SetContentText("My service started")
.SetOngoing(true);
NotificationManagerCompat notificationManager = NotificationManagerCompat.From(this);
StartForeground(NOTIFICATION_SERVICE_ID, builder.Build());
}
//every 5 seconds push a notificaition
private void DispatchNotificationThatAlarmIsGenerated(string message)
{
var intent = new Intent(this, typeof(MainActivity));
intent.AddFlags(ActivityFlags.ClearTop);
var pendingIntent = PendingIntent.GetActivity(this, 0, intent, PendingIntentFlags.OneShot);
Notification.Builder notificationBuilder = new Notification.Builder(this)
.SetSmallIcon(Resource.Drawable.Icon)
.SetContentTitle("Alarm")
.SetContentText(message)
.SetAutoCancel(true)
.SetContentIntent(pendingIntent);
var notificationManager = (NotificationManager)GetSystemService(NotificationService);
notificationManager.Notify(NOTIFICATION_AlARM_ID, notificationBuilder.Build());
}
}
2.in your activity :
protected override void OnResume()
{
base.OnResume();
StartMyRequestService();
}
public void StartMyRequestService()
{
var serviceToStart = new Intent(this, typeof(MyService));
StartService(serviceToStart);
}

try to start the service with
ContextCompat.startForegroundService(context,intent)
build the notification then call
startForeground(1, notification)
in onCreate() or onStartCommand() whatever works for you but after the service started and running don't forget to ask for permission
<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />

How to prevent android to stop a service with forground (for android version>O ) and notification

I want to take signal measurements. My app activity takes masurements (and provide charts) when is in foreground and at the onPause event I call and bind a service to take measurements (and store them in the database) in order to replace the activity.
However if the phone is unpluged the app stop taking measurements. I have study a lot of other posts and I have implemented in foreground with notification.
Here is a code sample from the Service
public int onStartCommand(Intent intent, int flags, int startId) {
super.onStartCommand(intent,START_STICKY,startId);
goForeground();
return Service.START_STICKY; }
private void goForeground() {
Log.i(TAG ,"goForeground");
Intent notificationIntent = new Intent(this, MainActivity.class);
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0,
notificationIntent, 0);
Notification n = new Notification.Builder(this)
.setContentTitle("Measurements Service")
.setContentText("App still collects measurements.")
.setSmallIcon(R.drawable.myApp)
.setContentIntent(pendingIntent)
.setPriority(Notification.PRIORITY_DEFAULT)
.setContentIntent(pendingIntent)
.build();
NotificationManager notificationManger =
(NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
notificationManger.notify(01, n);
startForeground(FOREGROUND_NOTIFICATION_ID, n);
}
and the MainActivity
Intent serviceIntent = new Intent(MainActivity.this, SnoopService.class);
if (SnoopService.isRunning()) {
Log.d(TAG, "Service is running");
doBindService(intent);
} else {
Log.d(TAG, "Service will run");
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
startForegroundService(intent);
} else
startService(intent);
doBindService(intent);
}
isBound = true;
}
Does anyone knows if I am doing something wrong?
I have test it with Samsung Galaxy S8.

Foreground Service dont run constantly

In my app I use a foreground service that must run constantly. Sometimes the foreground service is stopped.
Under what circumstances can the OS kill my service (it happen even if there is enough memory, battery is full, phone is charging)?
This is what my code looks like until now:
public class ServiceTest extends Service {
public static Thread serverThread = null;
public Context context = this;
public ServiceTest(Context context) {
super();
this.context = context;
}
public ServiceTest() {
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
super.onStartCommand(intent, flags, startId);
if (this.serverThread == null) {
this.serverThread = new Thread(new ThreadTest());
this.serverThread.start();
}
return START_STICKY;
}
private class ThreadTest implements Runnable {
#Override
public void run() {
Intent notificationIntent = new Intent(context, MainActivity.class);
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
PendingIntent pendingIntent = PendingIntent.getActivity(context, 0,
notificationIntent, PendingIntent.FLAG_CANCEL_CURRENT);
Notification notification = new NotificationCompat.Builder(context)
.setContentTitle("Notification title")
.setContentText("Notification text")
.setContentIntent(pendingIntent)
.setAutoCancel(false)
.setSmallIcon(R.drawable.android)
.setOngoing(true).build();
startForeground(101, notification);
while(true){
//work to do
}
}
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
}

There is not a single... Many problems in your code... You may be getting it "0 Errors" as it is syntactically correct but it is androidicaly wrong, your basics are poor, reading of android documentation and implementation is very poor. Android never runs very poor things...
Problem : 1
Do you know for a service conventionally you should override onCreate, onStartCommand, onBind, onDestroy methods....?
I don't see onDestroy there....!!
Problem : 2
Do you know how to notify...? Your onStartCommand implementation is again making no sense.
KEEP IT EMPTY JUST RETURN START_STICKY
Problem : 3
How do you expect to run this under background execution limits...? Notify android first by making notification in oncreate only and with startforeground if needed...
I don't see it there.... you trying to do it in onstartcommand and again it is very poorly...
Well... take a look at working code below :
public class RunnerService extends Service
{
NotificationManager mNotifyManager;
NotificationCompat.Builder mBuilder;
NotificationChannel notificationChannel;
String NOTIFICATION_CHANNEL_ID = "1";
public RunnerService() { }
#Override
public void onCreate()
{
super.onCreate();
Log.d("RUNNER : ", "OnCreate... \n");
Bitmap IconLg = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher_foreground);
mNotifyManager = (NotificationManager) getApplicationContext().getSystemService(NOTIFICATION_SERVICE);
mBuilder = new NotificationCompat.Builder(this, null);
mBuilder.setContentTitle("My App")
.setContentText("Always running...")
.setTicker("Always running...")
.setSmallIcon(R.drawable.ic_menu_slideshow)
.setLargeIcon(IconLg)
.setPriority(Notification.PRIORITY_HIGH)
.setVibrate(new long[] {1000})
.setVisibility(Notification.VISIBILITY_PUBLIC)
.setOngoing(true)
.setAutoCancel(false);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
{
notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID, "My Notifications", NotificationManager.IMPORTANCE_HIGH);
// Configure the notification channel.
notificationChannel.setDescription("Channel description");
notificationChannel.enableLights(true);
notificationChannel.setLightColor(Color.RED);
notificationChannel.setVibrationPattern(new long[]{1000});
notificationChannel.enableVibration(true);
notificationChannel.setLockscreenVisibility(Notification.VISIBILITY_PUBLIC);
mNotifyManager.createNotificationChannel(notificationChannel);
mBuilder.setChannelId(NOTIFICATION_CHANNEL_ID);
startForeground(1, mBuilder.build());
}
else
{
mBuilder.setChannelId(NOTIFICATION_CHANNEL_ID);
mNotifyManager.notify(1, mBuilder.build());
}
}
#Override
public int onStartCommand(Intent intent, int flags, int startId)
{
Log.d("RUNNER : ", "\nPERFORMING....");
return START_STICKY;
}
#Override
public void onDestroy()
{
Log.d("RUNNER : ", "\nDestroyed....");
Log.d("RUNNER : ", "\nWill be created again automaticcaly....");
super.onDestroy();
}
#Override
public IBinder onBind(Intent intent)
{
// TODO: Return the communication channel to the service.
throw new UnsupportedOperationException("NOT_YET_IMPLEMENTED");
}
}
How to check....???
Remove the app from recents list and you should see in your logs the "Performing " message in logcat...
In what conditions it stops...?
It never stops ( until next boot..!! )... Yes it stops when user force stops application. And rarely if system finds it is having very low resources .... which is a very rare condition seems to occur as android has improved a lot over the time....
How to start it....?????
Wherever it may be from mainactivity or from receiver or from any class :
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
{
context.startForegroundService(new Intent(context, RunnerService.class));
}
else
{
context.startService(new Intent(context, RunnerService.class));
}
How to check is service started or not....?
Simply Don't..... Even if you starts service how many times you wants.... If it is already running... then it won't be start again.... If not running then... will start it...!!

The criticism made in the chosen answer is not reasonable if the service needs an intent to work.
On higher version of Android, System will pause any foreground service while the device is locked, to minimize the power consumption even if it returns START_STICKY. So, to make a foreground task constantly, a wakelock is required.
Here's what android documentation describes wakeLock:
To avoid draining the battery, an Android device that is left idle quickly falls asleep. However, there are times when an application needs to wake up the screen or the CPU and keep it awake to complete some work.
To make a foreground service running constantly, acquire a wakeLock from inside the onCreate().
PowerManager powerManager = (PowerManager) getSystemService(POWER_SERVICE);
WakeLock wakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
"MyApp::MyWakelockTag");
wakeLock.acquire();
For further detail, have a look at official Android Documentation.

Starting a Service with Alarm after the app is closed

I am making a simple app that that consists of a service that pops a notification several times a day. I am trying to make this with a Alarm. All works perfect if I don't close the app. However, if I close the app when the receiver is triggered I get the message "the app has stopped working" or whatever.
I was wandering if it is because the service cannot work without an activity of the app or something? Any insights?
Here is my code:
The receiver:
public class AlarmReceiver extends BroadcastReceiver {
public static final int REQUEST_CODE = 12345;
public static final String ACTION = "com.ddimitrovd.hap4eapp4e.alarm";
// Triggered by the Alarm periodically (starts the service to run task)
#Override
public void onReceive(Context context, Intent intent) {
Intent i = new Intent(context, MainIntentService.class);
i.putExtra("foo", "bar");
context.startService(i);
}
}
Here is the Service:
public class MainIntentService extends IntentService {
int noteID = 1;
String chanelID;
public MainIntentService() {
super("MainIntentService");
}
#Override
protected void onHandleIntent(Intent intent) {
chanelID = getString(R.string.channel_ID);
Toast.makeText(this, "My Service Started", Toast.LENGTH_LONG).show();
// Do the task here
createNotificationChannel();
popNotif();
}
public void onDestroy() {
Toast.makeText(this, "My Service Stopped", Toast.LENGTH_LONG).show();
}
private void popNotif() {
// Create an explicit intent for an Activity in your app
Intent intent = new Intent(this, MainActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, 0);
NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this, chanelID)
.setSmallIcon(R.drawable.ic_launcher_foreground)
.setContentTitle("My notification")
.setContentText("Hello World!")
.setPriority(NotificationCompat.PRIORITY_DEFAULT)
// Set the intent that will fire when the user taps the notification
.setContentIntent(pendingIntent)
.setAutoCancel(true);
NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);
notificationManager.notify(noteID, mBuilder.build());
}
private void createNotificationChannel() {
// Create the NotificationChannel, but only on API 26+ because
// the NotificationChannel class is new and not in the support library
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
CharSequence name = getString(R.string.channel_name);
String description = getString(R.string.channel_description);
int importance = NotificationManager.IMPORTANCE_DEFAULT;
NotificationChannel channel = new NotificationChannel(chanelID, name, importance);
channel.setDescription(description);
// Register the channel with the system; you can't change the importance
// or other notification behaviors after this
NotificationManager notificationManager = getSystemService(NotificationManager.class);
notificationManager.createNotificationChannel(channel);
}
}
}
I am certain the alarm triggers the receiver.
Thank you!

I think that I found the problem. I reckon that my IntentService can not execute complexly because the BroadcastReceiver process is killed before it can do it. More info here.
What I did was simply to pop my notification in the receiver, but I guess a better solution would be to start another thread or to put it async.

Do not show notification if it is already shown

In my application I want show a notification in some cases.
When notification is active I do not want to create notification again.
I have activity recognition in my app and when it's detected that I am in car it starts to sound notification every second.
How could I prevent a new build notification if there is at least one active notification there?
Here is my code what I tried:
Intent closeIntent;
Intent showIntent;
if (isStart){
closeIntent = new Intent(this, SwitchButtonListener1.class);
} else {
closeIntent = new Intent(this, SwitchButtonListener2.class);
}
closeIntent.setAction("No");
PendingIntent pendingIntentClose = PendingIntent.getBroadcast(this, 0,
closeIntent, PendingIntent.FLAG_UPDATE_CURRENT);
NotificationCompat.Action closeAction = new NotificationCompat.Action(R.drawable.btn_close_gray, "No", pendingIntentClose);
if (isStart){
showIntent = new Intent(this, SwitchButtonListener1.class);
} else {
showIntent = new Intent(this, SwitchButtonListener2.class);
}
showIntent.setAction("Yes");
PendingIntent pendingIntentShow = PendingIntent.getBroadcast(this, 0,
showIntent, PendingIntent.FLAG_UPDATE_CURRENT);
NotificationCompat.Action showAction = new NotificationCompat.Action(R.drawable.ic_tick, "Yes", pendingIntentShow);
Uri alarmSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
NotificationCompat.Builder builder = new NotificationCompat.Builder(this)
.setWhen(System.currentTimeMillis())
.setAutoCancel(true)
.setSmallIcon(R.drawable.ic_stat_milebox)
.setContentTitle(title)
.setContentText(message)
.addAction(showAction)
.addAction(closeAction);
builder.setSound(alarmSound);
NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
mNotificationManager.notify(100, builder.build());

Though it is an old question, but I think this answer might help others in the future:
In a case like this, when the user needs to be notified only once and the event is ongoing then using .setOnlyAlertOnce(true) and setOngoing(true) with the builder will solve the problem.
Documentation:
setOnlyAlertOnce(true): Set this flag if you would only like the sound, vibrate and ticker to be played if the notification is not already showing.
setOngoing(true): Set whether this is an ongoing notification. Ongoing notifications cannot be dismissed by the user, so your application or service must take care of canceling them. They are typically used to indicate a background task that the user is actively engaged with (e.g., playing music) or is pending in some way and therefore occupying the device (e.g., a file download, sync operation, active network connection).
Notification notification = new NotificationCompat.Builder(this, notificationChannel.getId())
.....
.....
.setOngoing(true)
.setOnlyAlertOnce(true)
.....
.....
.build();
Objects.requireNonNull(notificationManager).notify(notificationId, notification);

You can try the following as a sketch:
public class MediaNotificationManager extends BroadcastReceiver {
private final NotificationManager mNotificationManager;
private Context ctx;
private boolean mStarted = false;
public MediaNotificationManager(Context ctx) {
mCtx = ctx;
mNotificationManager = (NotificationManager) ctx.getSystemService(Context.NOTIFICATION_SERVICE);
// Cancel all notifications to handle the case where the Service was killed and
// restarted by the system.
mNotificationManager.cancelAll();
}
/**
* Posts the notification and starts tracking the session to keep it
* updated. The notification will automatically be removed if the session is
* destroyed before {#link #stopNotification} is called.
*/
public void startNotification() {
if (!mStarted) {
// The notification must be updated after setting started to true
Notification notification = createNotification();
if (notification != null) {
mStarted = true;
}
}
}
/**
* Removes the notification and stops tracking the session. If the session
* was destroyed this has no effect.
*/
public void stopNotification() {
if (mStarted) {
mStarted = false;
try {
mNotificationManager.cancel(NOTIFICATION_ID);
} catch (IllegalArgumentException ex) {
// ignore if the receiver is not registered.
}
}
}
#Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
LogHelper.d(TAG, "Received intent with action " + action);
switch (action) {
//do something with this.
}
}
private Notification createNotification() {
//create and return the notification
}
}
For a bit more read this:
I also used this notification in my code:
https://github.com/googlesamples/android-UniversalMusicPlayer/blob/master/mobile/src/main/java/com/example/android/uamp/MediaNotificationManager.java