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Finish foreground service thread

I have a foreground service with a thread that is continuously checking data from a server.
So the service works well and it doesn't closes when I close the app, but when I start the app again the service creates another thread. Is posible abort the thread of the previous instance?
This is my MainActivity
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
public static Activity ActivityCurrent { get; private set; }
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
Window.SetStatusBarColor(Android.Graphics.Color.Rgb(0, 120, 71));
Xamarin.Essentials.Platform.Init(this, savedInstanceState);
global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
System.Diagnostics.Debug.WriteLine("Iniciado");
LoadApplication(new App());
ActivityCurrent = this;
DependencyService.Get<IServicio>().Start();
}
public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
{
Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);
base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
This is my service class
[Service(ForegroundServiceType = Android.Content.PM.ForegroundService.TypeDataSync)]
public class Servicio : Service, IServicio
{
Uri link = new Uri(new Url().Dir + "/estado_alarma.php");
public override IBinder OnBind(Intent intent)
{
throw new NotImplementedException();
}
[return: GeneratedEnum]
Thread refrescar;
public override StartCommandResult OnStartCommand(Intent intent, [GeneratedEnum] StartCommandFlags flags, int starId)
{
if (intent.Action == "START_SERVICE")
{
System.Diagnostics.Debug.WriteLine("Se ha iniciado el servicio");
RegisterNotification();
}
else if (intent.Action == "STOP_SERVICE")
{
StopForeground(true);
StopSelfResult(starId);
}
return StartCommandResult.NotSticky;
}
private void RegisterNotification()
{
NotificationChannel channel = new NotificationChannel("ServicioChannel", "Demo de servicio", NotificationImportance.Max);
NotificationManager manager = (NotificationManager)MainActivity.ActivityCurrent.GetSystemService(Context.NotificationService);
manager.CreateNotificationChannel(channel);
Notification notification = new Notification.Builder(this, "ServicioChannel").SetContentTitle("Servicio Trabajando").SetOngoing(true).Build();
StartForeground(200, notification);
_ = IniciarServicio();
}
public void Start()
{
Intent startService = new Intent(MainActivity.ActivityCurrent, typeof(Servicio));
startService.SetAction("START_SERVICE");
MainActivity.ActivityCurrent.StartService(startService);
}
public void Stop()
{
Intent startService = new Intent(MainActivity.ActivityCurrent, typeof(Servicio));
startService.SetAction("STOP_SERVICE");
MainActivity.ActivityCurrent.StartService(startService);
}
public int IniciarServicio()
{
refrescar = new Thread(EsperaAlarmaAsync);
refrescar.Start();
return 1;
}
public async void EsperaAlarmaAsync()
{
WebClient cliente = new WebClient();
byte[] respuesta;
string resultado;
var a = true;
while (a)
{
respuesta = cliente.DownloadData(link);
resultado = System.Text.Encoding.ASCII.GetString(respuesta);
cliente.Dispose();
if (resultado == "Alerta")
{
setNotificationVolumeToMax();
Device.BeginInvokeOnMainThread(() =>
{
App.Current.MainPage = new Alerta();
var powerManager = (PowerManager)GetSystemService(PowerService);
var wakeLock = powerManager.NewWakeLock(WakeLockFlags.ScreenDim | WakeLockFlags.AcquireCausesWakeup, "Ejemplo");
wakeLock.Acquire();
Intent x = new Intent(MainActivity.ActivityCurrent.Intent);
StartActivity(x);
});
a = false;
}
Thread.Sleep(3000);
}
refrescar.Abort();
}
private void setNotificationVolumeToMax()
{
try
{
var audioManager = (AudioManager)GetSystemService(Context.AudioService);
int max_volume = audioManager.GetStreamMaxVolume(Android.Media.Stream.Music);
audioManager.SetStreamVolume(Android.Media.Stream.Music, max_volume, 0);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
}
When the server return 'Alerta' it opens the app

Change text of TextView on ImageButton click

I am trying to change the text of a TextView an ImageButton click. However, when the button is pressed, the text does not change.
I have tried to use TextView tv = (TextView)findViewById(R.id.textView1);. However, I am not able to use FindViewById because I am working with RemoteViews.
The text of textView1 is set correctly OnUpdate, but does not change when the button is pressed. A button click is correctly registered as the Toast popup is displayed.
class WidgetClass : AppWidgetProvider
{
private Book latestBook;
public static String SaveClick = "Save Book";
public override void OnUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds)
{
var me = new ComponentName(context, Java.Lang.Class.FromType(typeof(WidgetClass)).Name);
appWidgetManager.UpdateAppWidget(me, BuildRemoteViews(context, appWidgetIds));
}
private RemoteViews BuildRemoteViews(Context context, int[] appWidgetIds)
{
var widgetView = new RemoteViews(context.PackageName, Resource.Layout.widget);
SetTextViewText(widgetView);
RegisterClicks(context, appWidgetIds, widgetView);
return widgetView;
}
private void SetTextViewText(RemoteViews widgetView)
{
CultureInfo currentCulture = Thread.CurrentThread.CurrentCulture;
widgetView.SetTextViewText(Resource.Id.textView1, latestBook.lastSaveTime.ToString("g", currentCulture));
}
private void RegisterClicks(Context context, int[] appWidgetIds, RemoteViews widgetView)
{
var intent = new Intent(context, typeof(WidgetClass));
intent.SetAction(AppWidgetManager.ActionAppwidgetUpdate);
intent.PutExtra(AppWidgetManager.ExtraAppwidgetIds, appWidgetIds);
widgetView.SetOnClickPendingIntent(Resource.Id.buttonSave, GetPendingSelfIntent(context, SaveClick));
}
private PendingIntent GetPendingSelfIntent(Context context, string action)
{
var intent = new Intent(context, typeof(WidgetClass));
intent.SetAction(action);
return PendingIntent.GetBroadcast(context, 0, intent, 0);
}
public override void OnReceive(Context context, Intent intent)
{
base.OnReceive(context, intent);
if (SaveClick.Equals(intent.Action))
{
Book book = new Book
{
lastSaveTime = DateTime.Now
};
App.Database.SaveBook(book);
latestBook = book;
Toast.MakeText(context, "New BookAdded", ToastLength.Short).Show();
var widgetView = new RemoteViews(context.PackageName, Resource.Layout.widget);
SetTextViewText(widgetView);
}
}
}
widget.xml:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="200dp"
android:layout_height="wrap_content"
android:layout_marginRight="0.0dp">
<ImageButton
android:id="#+id/buttonSave"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:layout_width="65dp"
android:layout_height="65dp"
android:scaleType="fitCenter"/>
<TextView
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:layout_width="135dp"
android:layout_height="wrap_content"
android:id="#+id/textView1"/>
</RelativeLayout>
</LinearLayout>
How can I update the text of textView1 when buttonSave is clicked?

You are creating new remoteview in OnReceive method. You should use existing one. I have updated code. Please check and update me.
class WidgetClass : AppWidgetProvider
{
private Book latestBook;
public static String SaveClick = "Save Book";
RemoteViews remoteView = null;
public override void OnUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds)
{
var me = new ComponentName(context, Java.Lang.Class.FromType(typeof(WidgetClass)).Name);
appWidgetManager.UpdateAppWidget(me, BuildRemoteViews(context, appWidgetIds));
}
private RemoteViews BuildRemoteViews(Context context, int[] appWidgetIds)
{
var widgetView = new RemoteViews(context.PackageName, Resource.Layout.widget);
SetTextViewText(widgetView);
RegisterClicks(context, appWidgetIds, widgetView);
remoteView = widgetView;
return widgetView;
}
private void SetTextViewText(RemoteViews widgetView)
{
CultureInfo currentCulture = Thread.CurrentThread.CurrentCulture;
widgetView.SetTextViewText(Resource.Id.textView1, latestBook.lastSaveTime.ToString("g", currentCulture));
}
private void RegisterClicks(Context context, int[] appWidgetIds, RemoteViews widgetView)
{
var intent = new Intent(context, typeof(WidgetClass));
intent.SetAction(AppWidgetManager.ActionAppwidgetUpdate);
intent.PutExtra(AppWidgetManager.ExtraAppwidgetIds, appWidgetIds);
widgetView.SetOnClickPendingIntent(Resource.Id.buttonSave, GetPendingSelfIntent(context, SaveClick));
}
private PendingIntent GetPendingSelfIntent(Context context, string action)
{
var intent = new Intent(context, typeof(WidgetClass));
intent.SetAction(action);
return PendingIntent.GetBroadcast(context, 0, intent, 0);
}
public override void OnReceive(Context context, Intent intent)
{
base.OnReceive(context, intent);
if (SaveClick.Equals(intent.Action))
{
Book book = new Book
{
lastSaveTime = DateTime.Now
};
App.Database.SaveBook(book);
latestBook = book;
Toast.MakeText(context, "New BookAdded", ToastLength.Short).Show();
SetTextViewText(remoteView);
}
}
}

Call Android Function From Xamarin.Forms

I have made an Xamarin.Android Widget with a Button and TextView. I have an instance of product (latestProduct) declared in App.cs. A new product is assigned to latestProduct when a new product is added.
The user is able to save a new record by clicking a Button (BtnAdd) on a Xamarin.Forms page. I am trying to update the Widget TextView when the user clicks this Button.
MyPage:
void BtnAdd_Clicked(object sender, EventArgs e) {
Product product = new Product
{
ProductSaveTime = DateTime.Now
};
App.Database.SaveProduct(product);
App.latestProduct = product;
DependencyService.Get<IUpdateDataService>().UpdateWidgetUI();
}
App.cs:
public static Product latestProduct;
IUpdateDataService.cs:
public interface IUpdateDataService
{
void UpdateWidgetUI();
}
WidgetClass.cs:
public class WidgetClass : AppWidgetProvider, IUpdateDataService
{
public static String SaveClick = "Save Product";
public override void OnUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds)
{
var me = new ComponentName(context, Java.Lang.Class.FromType(typeof(WidgetClass)).Name);
appWidgetManager.UpdateAppWidget(me, BuildRemoteViews(context, appWidgetIds));
}
private RemoteViews BuildRemoteViews(Context context, int[] appWidgetIds)
{
var widgetView = new RemoteViews(context.PackageName, Resource.Layout.widget);
UpdateData(widgetView);
RegisterClicks(context, appWidgetIds, widgetView);
return widgetView;
}
private void UpdateData(RemoteViews widgetView)
{
CultureInfo currentCulture = Thread.CurrentThread.CurrentCulture;
widgetView.SetTextViewText(Resource.Id.textView1, "Last Product: " + App.latestProduct.ProductSaveTime.ToString("g", currentCulture));
}
private void RegisterClicks(Context context, int[] appWidgetIds, RemoteViews widgetView)
{
var intent = new Intent(context, typeof(WidgetClass));
intent.SetAction(AppWidgetManager.ActionAppwidgetUpdate);
intent.PutExtra(AppWidgetManager.ExtraAppwidgetIds, appWidgetIds);
widgetView.SetOnClickPendingIntent(Resource.Id.buttonSave, GetPendingSelfIntent(context, SaveClick));
}
private PendingIntent GetPendingSelfIntent(Context context, string action)
{
var intent = new Intent(context, typeof(WidgetClass));
intent.SetAction(action);
return PendingIntent.GetBroadcast(context, 0, intent, 0);
}
public override void OnReceive(Context context, Intent intent)
{
base.OnReceive(context, intent);
if (SaveClick.Equals(intent.Action))
{
Product product = new Product
{
ProductSaveTime = DateTime.Now
};
App.latestProduct = product;
RemoteViews remoteViews = new RemoteViews(context.PackageName, Resource.Layout.widget);
UpdateData(remoteViews);
AppWidgetManager appWidgetManager = AppWidgetManager.GetInstance(context);
ComponentName componentName = new ComponentName(context, Java.Lang.Class.FromType(typeof(WidgetClass)).Name);
appWidgetManager.UpdateAppWidget(componentName, remoteViews);
}
}
public void UpdateWidgetUI()
{
var widgetView = new RemoteViews(context.PackageName, Resource.Layout.widget);
UpdateData(widgetView);
AppWidgetManager appWidgetManager = AppWidgetManager.GetInstance(context);
ComponentName componentName = new ComponentName(context, Java.Lang.Class.FromType(typeof(WidgetClass)).Name);
appWidgetManager.UpdateAppWidget(componentName, remoteViews);
}
}
When BtnAdd is clicked, how can I use DependecyService to call UpdateData()? The problem I have is 'context' does not exist in the current context in UpdateWidgetUI();

You could make your MainActivity as a static variable.
like:
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
public static MainActivity Instance;
protected override void OnCreate(Bundle savedInstanceState)
{
TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;
base.OnCreate(savedInstanceState);
Instance = this;
Xamarin.Essentials.Platform.Init(this, savedInstanceState);
global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
LoadApplication(new App());
}
}
then you want use the context,you could do like:
public void UpdateWidgetUI()
{
var widgetView = new RemoteViews(MainActivity.Instance.PackageName, Resource.Layout.widget);
UpdateData(widgetView);
AppWidgetManager appWidgetManager = AppWidgetManager.GetInstance(MainActivity.Instance);
ComponentName componentName = new ComponentName(MainActivity.Instance, Java.Lang.Class.FromType(typeof(WidgetClass)).Name);
appWidgetManager.UpdateAppWidget(componentName, remoteViews);
}

The parameter came from broadcast receiver constructor is always nullable

I want to update my main activity UI in my foreground service with broadcast receiver. In BroadcastReceiver.OnReceive method,I passed the instance of main activity,but it is always nullable. How can I fix it? Many thanks in advance!
In my broadcast receiver:
public override void OnReceive(Context context, Intent intent)
{
Core.Music music = intent.GetParcelableExtra("selectedMusic") as Core.Music;
mMainActivity.mTxtSongName.Text = Core.MusicHelper.GetTitleAndAuthor(music.Title);
mMainActivity.mTxtAuthorName.Text = Core.MusicHelper.GetTitleAndAuthor(music.Author);
System.Threading.ThreadPool.QueueUserWorkItem(o =>
{
string imageUrl = music.Url.Replace(#"\", "").Replace("http", "https");
var task = Core.MusicHelper.GetSongPic(imageUrl, 35, 35);
var pic = task.Result;
if (pic != null)
{
mMainActivity.RunOnUiThread(() =>
{
mMainActivity.mImageViewSongPic.SetImageBitmap(pic);
});
}
});
}
In my service:
public override StartCommandResult OnStartCommand(Intent intent, [GeneratedEnum] StartCommandFlags flags, int startId)
{
Core.Music music = intent.GetParcelableExtra("selectedMusic") as Core.Music;
BroadcastStarted(music);
//To start the service
return StartCommandResult.NotSticky;
}
In my MainActivity.OnResume:
IntentFilter filter = new IntentFilter();
mReceive = new Service.Boradcast.MusicChangedBroadcastReceiver() { mMainActivity=this};
RegisterReceiver(mReceive,filter);

how do you defined mMainActivity ?
however the simplest example of a reference to MainActivity is to use static
define in your MainActivity OnCreate() method:
public static MainActivity Instance;
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
...
Instance = this;
}
then call in your broadcast receiver
public override void OnReceive(Context context, Intent intent)
{
Core.Music music = intent.GetParcelableExtra("selectedMusic") as Core.Music;
MainActivity.Instance.mTxtSongName.Text = Core.MusicHelper.GetTitleAndAuthor(music.Title);
MainActivity.Instance.mTxtAuthorName.Text = Core.MusicHelper.GetTitleAndAuthor(music.Author);
System.Threading.ThreadPool.QueueUserWorkItem(o =>
{
string imageUrl = music.Url.Replace(#"\", "").Replace("http", "https");
var task = Core.MusicHelper.GetSongPic(imageUrl, 35, 35);
var pic = task.Result;
if (pic != null)
{
MainActivity.Instance.RunOnUiThread(() =>
{
MainActivity.Instance.mImageViewSongPic.SetImageBitmap(pic);
});
}
});
}
Or pass MainActivity as a parameter to the constructor ：
in your MainActivity.OnResume():
IntentFilter filter = new IntentFilter();
mReceive = new Service.Boradcast.MusicChangedBroadcastReceiver(this);
RegisterReceiver(mReceive,filter);
then in your broadcast receiver：
[BroadcastReceiver]
public class MusicChangedBroadcastReceiver: BroadcastReceiver
{
public MainActivity mMainActivity;
public MusicChangedBroadcastReceiver()
{
}
public MusicChangedBroadcastReceiver(MainActivity activity)
{
this.mMainActivity= activity;
}
public override void OnReceive(Context context, Intent intent)
{
Core.Music music = intent.GetParcelableExtra("selectedMusic") as Core.Music;
mMainActivity.mTxtSongName.Text = Core.MusicHelper.GetTitleAndAuthor(music.Title);
mMainActivity.mTxtAuthorName.Text = Core.MusicHelper.GetTitleAndAuthor(music.Author);
System.Threading.ThreadPool.QueueUserWorkItem(o =>
{
string imageUrl = music.Url.Replace(#"\", "").Replace("http", "https");
var task = Core.MusicHelper.GetSongPic(imageUrl, 35, 35);
var pic = task.Result;
if (pic != null)
{
mMainActivity.RunOnUiThread(() =>
{
mMainActivity.mImageViewSongPic.SetImageBitmap(pic);
});
}
});
}
}

Auth0 logout issue in Xamarin.Android

Currently in my Xamairn.Android I have 2 activities Mainactivity and SignoutActivity.
In my Mainactivity I have a button where when user clicks the button it goes to SignoutActivity.
Here I have implemented the signout codes of Auth0.
Here are the codes-
In MainAcitivity-
this.Signout.Click += delegate
{
using (var intent = new Intent(this, typeof(SignOutActivity)))
{
this.StartActivity(intent);
}
};
SignOutAcitivity-
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
this.LogoutAsync();
Finish();
}
public async Task<BrowserResult> LogoutAsync()
{
var clientOptions = new Auth0.OidcClient.Auth0ClientOptions
{
Domain ="",
ClientId = "",
Scope = "openid email offline_access",
Browser = new PlatformWebView()
};
var logoutUrl = "Signout URl";
string redirectUri = "I have proper callback uri";
Dictionary<string, string> dictionary = new Dictionary<string, string>();
dictionary.Add("client_id", "random1234");
dictionary.Add("returnTo", clientOptions.RedirectUri);
string endSessionUrl = new RequestUrl(logoutUrl).Create(dictionary);
var logoutRequest = new LogoutRequest();
BrowserResult browserResult = null;
browserResult = await clientOptions.Browser.InvokeAsync(new BrowserOptions(endSessionUrl, redirectUri)
{
Timeout = TimeSpan.FromSeconds((double)logoutRequest.BrowserTimeout),
DisplayMode = logoutRequest.BrowserDisplayMode
});
return browserResult;
}
Platformview-
class PlatformWebView : IBrowser
{
public Task<BrowserResult> InvokeAsync(BrowserOptions options)
{
if (string.IsNullOrWhiteSpace(options.StartUrl))
{
throw new ArgumentException("Missing StartUrl", nameof(options));
}
if (string.IsNullOrWhiteSpace(options.EndUrl))
{
throw new ArgumentException("Missing EndUrl", nameof(options));
}
var tcs = new TaskCompletionSource<BrowserResult>();
void Callback(string response)
{
ActivityMediator.Instance.ActivityMessageReceived -= Callback;
// set result
if (response == "UserCancel")
{
tcs.SetResult(new BrowserResult { ResultType = BrowserResultType.UserCancel });
}
else
{
tcs.SetResult(new BrowserResult
{
Response = response,
ResultType = BrowserResultType.Success
});
}
}
ActivityMediator.Instance.ActivityMessageReceived += Callback;
var uri = Android.Net.Uri.Parse(options.StartUrl);
var intent = new Intent(Intent.ActionView, uri);
intent.AddFlags(ActivityFlags.NoHistory)
.AddFlags(ActivityFlags.NewTask);
Application.Context.StartActivity(intent);
return tcs.Task;
}
}
}
Problem is browser never returns to app,Also I have put a debugger at return browserResult,this debugger also does not hit.Please help me.