receive message from android beam in xamarin forms - xamarin.forms

I'm develop cross-platform mobile application that use NFC. I already check the xamarin android beam sample here. Now i'm trying implement the same sample using xamarin forms so i'm using dependency service to call the function from android project.
I already create Ndef message and send function:
using System;
using System.Text;
using Android.App;
using MyApp.Droid;
using Android.Nfc;
using Xamarin.Forms;
[assembly: Dependency(typeof(PhoneBeam))]
namespace MyApp.Droid
{
public class PhoneBeam : Activity, NfcAdapter.ICreateNdefMessageCallback, NfcAdapter.IOnNdefPushCompleteCallback, iBeam
{
private NfcAdapter nfcAdapter;
public void Beam()
{
nfcAdapter = NfcAdapter.GetDefaultAdapter(MainActivity.Instance);
nfcAdapter.SetNdefPushMessageCallback(this, MainActivity.Instance);
nfcAdapter.SetOnNdefPushCompleteCallback(this, MainActivity.Instance);
}
public NdefMessage CreateNdefMessage(NfcEvent evt)
{
DateTime time = DateTime.Now;
var text = ("Beam me up!\n\n" + "Beam : " +
time.ToString("HH:mm:ss"));
NdefMessage msg = new NdefMessage(
new NdefRecord[]{ CreateMimeRecord (
"application/com.companyname.MyApp",
Encoding.UTF8.GetBytes (text)) });
return msg;
}
public NdefRecord CreateMimeRecord(String mimeType, byte[] payload)
{
byte[] mimeBytes = Encoding.UTF8.GetBytes(mimeType);
NdefRecord mimeRecord = new NdefRecord(
NdefRecord.TnfMimeMedia, mimeBytes, new byte[0], payload);
return mimeRecord;
}
public void OnNdefPushComplete(NfcEvent e){}
}
}
However, I really don't know how to receive a message. In android beam sample, they implement it in mainactivity. Here's sample:
protected override void OnResume ()
{
base.OnResume ();
if (NfcAdapter.ActionNdefDiscovered == Intent.Action) {
ProcessIntent (Intent);
}
}
void ProcessIntent (Intent intent)
{
IParcelable [] rawMsgs = intent.GetParcelableArrayExtra (
NfcAdapter.ExtraNdefMessages);
NdefMessage msg = (NdefMessage) rawMsgs [0];
mInfoText.Text = Encoding.UTF8.GetString (msg.GetRecords () [0].GetPayload ());
}
So i want to implement in class file so i can use dependencyService. Is there a way to implement this?
Edit: I did the send function:
public NdefMessage CreateNdefMessage (NfcEvent evt)
{
DateTime time = DateTime.Now;
var text = ("Beam me up!\n\n" +
"Beam Time: " + time.ToString ("HH:mm:ss"));
NdefMessage msg = new NdefMessage (
new NdefRecord[] { CreateMimeRecord (
"application/com.companyname.MyApp", Encoding.UTF8.GetBytes (text))
});
return msg;
}
But it return as "NEW TAG COLLECTED: application/com.companyname.MyApp". I want to resume MyApp and show the message. But it didn't.

Related

DependencyService.Get<ILogManager>().GetLog() System.NullReferenceException: 'Object reference not set to an instance of an object'

I am trying to execute Xamarin App.
I can build and deploy solutions on both Android and iOS devices. But when I am Debugging/running iOS App I am receiving an error
**System.NullReferenceException:** 'Object reference not set to an instance of an object'
on
private static ILogger logger = DependencyService.Get<ILogManager>().GetLog(); line
I have installed the latest version of the Nlog NuGet Package.
My ILogManager file is
namespace VolMobile.AppData.Interfaces
{
public interface ILogManager
{
ILogger GetLog([System.Runtime.CompilerServices.CallerFilePath]string callerFilePath = "");
void Reload();
void DeleteLog();
}
}
How can I resolve this issue?
update
My NLogManager iOS file
using System;
using System.Collections.Generic;
using Xamarin.Forms;
using System.IO;
using NLog;
using NLog.Config;
using NLog.Targets;
using VolMobile.AppData.Interfaces;
using VolMobile.iOS.Logging;
[assembly: Dependency(typeof(NLogManager))]
namespace VolMobile.iOS.Logging
{
public class NLogManager : ILogManager
{
string logFile;
LoggingConfiguration config;
public NLogManager()
{
Reload();
}
public void Reload()
{
config = new LoggingConfiguration();
var consoleTarget = new ConsoleTarget();
config.AddTarget("console", consoleTarget);
var consoleRule = new LoggingRule("*", LogLevel.Trace, consoleTarget);
config.LoggingRules.Add(consoleRule);
//File logging level
LogLevel llSetting = LogLevel.Off;
IEnumerable<LogLevel> sysLevels = LogLevel.AllLevels;
//default to trace at startup
string currentLogLevel = "Trace";
//load the app state if available
if (App.AppState != null)
currentLogLevel = App.AppState.AppSettings.LogLevel;// AppData.AppData.LogLevel;
foreach (LogLevel ll in sysLevels)
{
if (currentLogLevel == ll.Name)
{
llSetting = ll;
}
}
var fileTarget = new FileTarget();
string folder = System.Environment.GetFolderPath(System.Environment.SpecialFolder.MyDocuments); //android.os.environment is the other option
fileTarget.FileName = Path.Combine(folder, "Log.txt");
fileTarget.Layout = "${longdate}|${level:uppercase=true}|${callsite}|${appdomain}|${logger}|${threadid}|${message}|{exception:format=tostring}";
config.AddTarget("file", fileTarget);
logFile = Path.Combine(folder, "Log.txt");
var fileRule = new LoggingRule("*", llSetting, fileTarget);//LogLevel.Warn
config.LoggingRules.Add(fileRule);
LogManager.Configuration = config;
}
public void DeleteLog()
{
File.Delete(logFile);
}
// Services.Logging.ILogger
//AppData.Interfaces.ILogger
//public NLogLogger GetLog([System.Runtime.CompilerServices.CallerFilePath] string callerFilePath = "")
//{
// string fileName = callerFilePath;
// if (fileName.Contains("/"))
// {
// fileName = fileName.Substring(fileName.LastIndexOf("/", StringComparison.CurrentCultureIgnoreCase) + 1);
// }
// var logger = LogManager.GetLogger(fileName);
// return new NLogLogger(logger, logFile);
//}
public AppData.Interfaces.ILogger GetLog([System.Runtime.CompilerServices.CallerFilePath] string callerFilePath = "")
{
string fileName = callerFilePath;
if (fileName.Contains("/"))
{
fileName = fileName.Substring(fileName.LastIndexOf("/", StringComparison.CurrentCultureIgnoreCase) + 1);
}
var logger = LogManager.GetLogger(fileName);
return new NLogLogger(logger, logFile);
}
}
}
The app is working perfectly fine on iOS, Andriod simulators, and Android Device only not on iOS devices.

"Save Photos in Photo albums of iPhone or iPad using Xamarin Forms" However PCL is Deprecated

I am trying do to the thing that is the question in this Stack Overflow Post "https://stackoverflow.com/questions/49291495/save-photos-in-photo-albums-of-iphone-or-ipad-using-xamarin-forms". However in the answer for the post PCL is deprecated. What is a more updated answer? Thank you.
However in the answer for the post PCL is deprecated.
Actually , you just need to do the same thing in Share Projects . DependencyService is available in Xamarin.Forms , which you can refer https://learn.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/dependency-service/introduction .
in Forms
public interface ISavePhotosToAlbum
{
void SavePhotosWithStream(string name, Stream data);
}
in iOS
[assembly: Dependency(typeof(SaveToAlbum))]
namespace xxx.iOS
{
public class SaveToAlbum : ISavePhotosToAlbum
{
public void SavePhotosWithStream(string name,Stream stream)
{
var imageData = NSData.FromStream(stream);
var image = UIImage.LoadFromData(imageData);
image.SaveToPhotosAlbum((img, error) =>
{
});
}
}
}
And add the following code in info.plist
<key>NSCameraUsageDescription</key>
<string>App need to access your camera</string>
<key>NSPhotoLibraryAddUsageDescription</key>
<string>App need to access your albums</string> // new in iOS 11 and later
<key>NSPhotoLibraryUsageDescription</key>
<string>App need to access your albums</string>
In addition , if you want to implement it in Android
in Android
[assembly: Dependency(typeof(SaveToAlbum))]
namespace xxx.Droid
{
public class SaveToAlbum : ISavePhotosToAlbum
{
public void SavePhotosWithStream(string name,Stream stream)
{
var documentsPath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
documentsPath = Path.Combine(documentsPath, "Orders", temp);
Directory.CreateDirectory(documentsPath);
string filePath = Path.Combine(documentsPath, name);
byte[] bArray = new byte[data.Length];
using (FileStream fs = new FileStream(filePath , FileMode.OpenOrCreate))
{
using (data)
{
data.Read(bArray, 0, (int)data.Length);
}
int length = bArray.Length;
fs.Write(bArray, 0, length);
}
}
}
}

need to send local notification even after killing my app using xamarin.forms

I am using xamarin forms for my app. I need to send local notification based on SQLite table for ios. I am using the following code:
AppDelegate.cs:
using System;
using Foundation;
using UIKit;
using Xamarin.Forms;
using Firebase.Database;
using Firebase.CloudMessaging;
using UserNotifications;
using Microsoft.AppCenter.Crashes;
using Plugin.Permissions;
using Plugin.Permissions.Abstractions;
using CoreTelephony;
using Firebase.Auth;
using System.Threading.Tasks;
using System.Collections.Generic;
namespace MyApp.iOS
{
[Register("AppDelegate")]
public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate, IUNUserNotificationCenterDelegate, IMessagingDelegate
{
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
global::Xamarin.Forms.Forms.Init();
AppDomain.CurrentDomain.UnhandledException += CurrentDomainOnUnhandledException;
Firebase.Core.App.Configure();
Database.DefaultInstance.PersistenceEnabled = true;
LoadApplication(new MyApp.App());
RegisterForRemoteNotifications();
Messaging.SharedInstance.Delegate = this;
if (UNUserNotificationCenter.Current != null)
{
UNUserNotificationCenter.Current.Delegate = new UserNotificationCenterDelegate();
}
if (UNUserNotificationCenter.Current != null)
{
UNUserNotificationCenter.Current.Delegate = new UserNotificationCenterDelegate();
}
Xamarin.FormsMaps.Init();
UIApplication.SharedApplication.IdleTimerDisabled = true;
UIApplication.SharedApplication.SetMinimumBackgroundFetchInterval(UIApplication.BackgroundFetchIntervalMinimum);
return base.FinishedLaunching(app, options);
}
public override bool ShouldRestoreApplicationState(UIApplication application, NSCoder coder)
{
return true;
}
private async System.Threading.Tasks.Task AcessPermissionsAsync()
{
try
{
await CrossPermissions.Current.RequestPermissionsAsync(Permission.Camera);
}
catch(Exception ex)
{
Crashes.TrackError(ex);
}
}
private void RegisterForRemoteNotifications()
{
if (UIDevice.CurrentDevice.CheckSystemVersion(10, 0))
{
UNUserNotificationCenter.Current.RemoveAllPendingNotificationRequests(); // To remove all pending notifications which are not delivered yet but scheduled.
UNUserNotificationCenter.Current.RemoveAllDeliveredNotifications(); // To remove all delivered notifications
}
else
{
UIApplication.SharedApplication.CancelAllLocalNotifications();
}
// Register your app for remote notifications.
if (UIDevice.CurrentDevice.CheckSystemVersion(10, 0))
{
// For iOS 10 display notification (sent via APNS)
UNUserNotificationCenter.Current.Delegate = this;
var authOptions = UNAuthorizationOptions.Alert | UNAuthorizationOptions.Badge | UNAuthorizationOptions.Sound;
UNUserNotificationCenter.Current.RequestAuthorization(authOptions, async (granted, error) =>
{
Console.WriteLine(granted);
await System.Threading.Tasks.Task.Delay(500);
await AcessPermissionsAsync();
});
}
else
{
// iOS 9 or before
var allNotificationTypes = UIUserNotificationType.Alert | UIUserNotificationType.Badge | UIUserNotificationType.Sound;
var settings = UIUserNotificationSettings.GetSettingsForTypes(allNotificationTypes, null);
UIApplication.SharedApplication.RegisterUserNotificationSettings(settings);
}
UIApplication.SharedApplication.RegisterForRemoteNotifications();
}
public override void DidEnterBackground(UIApplication uiApplication)
{
Messaging.SharedInstance.ShouldEstablishDirectChannel = false;
}
public override void RegisteredForRemoteNotifications(UIApplication application, NSData deviceToken)
{
Messaging.SharedInstance.ApnsToken = deviceToken;
}
[Export("messaging:didReceiveRegistrationToken:")]
public void DidReceiveRegistrationToken(Messaging messaging, string fcmToken)
{
Xamarin.Forms.Application.Current.Properties["Fcmtocken"] = Messaging.SharedInstance.FcmToken ?? "";
Xamarin.Forms.Application.Current.SavePropertiesAsync();
System.Diagnostics.Debug.WriteLine($"######Token###### : {fcmToken}");
DeviceId.FCMTocken = fcmToken;
// TODO: If necessary send token to application server.
// Note: This callback is fired at each app startup and whenever a new token is generated.
}
public override void ReceivedRemoteNotification(UIApplication application, NSDictionary userInfo)
{
// If you are receiving a notification message while your app is in the background,
// this callback will not be fired till the user taps on the notification launching the application.
// TODO: Handle data of notification
// With swizzling disabled you must let Messaging know about the message, for Analytics
// Print full message.
Console.WriteLine(userInfo);
}
public override void DidReceiveRemoteNotification(UIApplication application, NSDictionary userInfo, Action<UIBackgroundFetchResult> completionHandler)
{
try
{
Console.WriteLine(userInfo);
completionHandler(UIBackgroundFetchResult.NewData);
}
catch(Exception ex)
{
Crashes.TrackError(ex);
}
}
public override UIInterfaceOrientationMask GetSupportedInterfaceOrientations(UIApplication application, UIWindow forWindow)
{
switch (Device.Idiom)
{
case TargetIdiom.Phone:
return UIInterfaceOrientationMask.Portrait;
case TargetIdiom.Tablet:
return UIInterfaceOrientationMask.Landscape;
default:
return UIInterfaceOrientationMask.Portrait;
}
}
private void CurrentDomainOnUnhandledException(object sender, UnhandledExceptionEventArgs unhandledExceptionEventArgs)
{
var newExc = new Exception("CurrentDomainOnUnhandledException", unhandledExceptionEventArgs.ExceptionObject as Exception);
ExceptionFileWriter.ToLogUnhandledException(newExc);
}
public void DidRefreshRegistrationToken(Messaging messaging, string fcmToken)
{
Xamarin.Forms.Application.Current.Properties["Fcmtocken"] = Messaging.SharedInstance.FcmToken ?? "";
Xamarin.Forms.Application.Current.SavePropertiesAsync();
System.Diagnostics.Debug.WriteLine($"######Token###### : {fcmToken}");
DeviceId.FCMTocken = fcmToken;
}
public override void PerformFetch(UIApplication application, Action<UIBackgroundFetchResult> completionHandler)
{
try
{
var baseService = new DatabaseServices<object, object>();
baseService.NotificationAssetTrip();
}
catch(Exception ex)
{
Logs.LogCreate("PerformFetch:Exception: " + ex.Message.ToString());
}
completionHandler(UIBackgroundFetchResult.NewData);
}
}
}
UserNotificationCenterDelegate.cs:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Foundation;
using iAd;
using ObjCRuntime;
using UIKit;
using UserNotifications;
namespace MyApp.iOS
{
public class UserNotificationCenterDelegate : UNUserNotificationCenterDelegate
{
private DBService dataBase;
#region Constructors
public UserNotificationCenterDelegate()
{
UNUserNotificationCenter.Current.Delegate = this;
}
#endregion
#region Override Methods
public override void WillPresentNotification(UNUserNotificationCenter center, UNNotification notification, Action<UNNotificationPresentationOptions> completionHandler)
{
completionHandler.DynamicInvoke(UNNotificationPresentationOptions.Alert);
}
#endregion
}
}
App.xaml.cs:
private void SendNotificationTripAsset(int tripid)
{
//Forexample i have table with columns like title,subtitle,message means, i give like this
var content = new UserNotifications.UNMutableNotificationContent()
{
Title = title,
Subtitle = subtitle,
Body = message,
Badge = 1
};
var request = UserNotifications.UNNotificationRequest.FromIdentifier(list.TripID.ToString(), content, null);
UserNotifications.UNUserNotificationCenter.Current.AddNotificationRequest(request, (err) =>
{
if (err != null)
{
throw new Exception($"Failed to schedule notification: {err}");
}
});
}
But the notification is not trigged after app is killed(terminated). Can anyone please help me to resolve this issue.
To send a local notification when app is killed, you have to specify the time when should the local notification been sent. In your code, when you create the request, set a proper NNotificationTrigger :
NNotificationTrigger trigger = UNTimeIntervalNotificationTrigger.CreateTrigger(3, false);
var request = UserNotifications.UNNotificationRequest.FromIdentifier(list.TripID.ToString(), content, trigger );
That means this notification will be fired after 3 seconds. You can change the time to whatever you want.
Code will not execute when your app is killed, so if you don't know the specific time to fire the notification or it fires randomly, you should use a remote notification.

Xamarin.Forms and Plugin.Media: after about 20 photos something crashes

I have a problem with Xamarin.Forms ver. 2.3.4.224 and Plugin.Media ver. 2.6.2. The problem occurs after taking about 20 photos (depends from the device): basically the app crashes without any apparently reason.
If you want to replicate the error, I created a test project for you on GitHub. With my iPad Air or iPad Pro after about 30 photos (video iPad Air - iPad Pro). All devices are iOS ver. 10.3.1 and they have enough space to storage photos.
The app is very simple: you have two buttons one for taking a picture and the other one to pick a photo. If you take photos one after another, after about 20 (32 in an iPad Air) the app crashes. I'm just take photos with the Plugin.Media nothing more.
Any ideas are welcome.
Update
In my project I had a reference to Refractored.MvvmHelpers and I noticed if I remove it, I can take more pictures. I created my BaseViewModel with INotifyPropertyChanged and I noticed I can take more photos.
I created then a new project (you can find it on GitHub under cameratesteasy) without MVVM and there is just the code to take a photo like:
public partial class cameratesteasyPage : ContentPage
{
int count = 0;
public cameratesteasyPage()
{
InitializeComponent();
CrossMedia.Current.Initialize();
}
void UpdateCount()
{
count++;
CountLabel.Text = $"{count} times";
}
async void StartCameraTapped(object sender, System.EventArgs args)
{
using (var file = await CrossMedia.Current.TakePhotoAsync(
new StoreCameraMediaOptions {}))
{
if (file == null)
return;
UpdateCount();
}
}
async void StartCameraTakeTapped(object sender, System.EventArgs args)
{
var file = await CrossMedia.Current.PickPhotoAsync();
if (file == null)
return;
UpdateCount();
}
}
In this case the app shut down after 52 photos. I saved the log for Xcode and you can see it here.
I used Xamarin Profile and the memory level is always low. After about 30 photos, an error occurs in Xamarin Profiler
Finally I could create a Xamarin Profiler file
Also I noticed this kind of error occurs on iPads. The same app in an iPhone is working fine (apparently) or I didn't find up to now the number of photos before crashing.
Update /2
I decided to implement a native function for taking photo.
Interface
public interface ICamera
{
void TakePicture();
}
Implementation
using System;
using cameratest.iOS;
using Foundation;
using UIKit;
using Xamarin.Forms;
[assembly: Xamarin.Forms.Dependency(typeof(Camera_iOS))]
namespace cameratest.iOS
{
public class Camera_iOS : ICamera
{
static UIImagePickerController picker;
static Action<NSDictionary> _callback;
static void Init()
{
if (picker != null)
return;
picker = new UIImagePickerController();
picker.Delegate = new CameraDelegate();
}
class CameraDelegate : UIImagePickerControllerDelegate
{
public override void FinishedPickingMedia(
UIImagePickerController picker, NSDictionary info)
{
var cb = _callback;
_callback = null;
picker.DismissModalViewController(true);
cb(info);
}
}
public static void TakePicture(UIViewController parent,
Action<NSDictionary> callback)
{
Init();
picker.SourceType = UIImagePickerControllerSourceType.Camera;
_callback = callback;
parent.PresentModalViewController(picker, true);
}
public static void SelectPicture(UIViewController parent,
Action<NSDictionary> callback)
{
Init();
picker.SourceType = UIImagePickerControllerSourceType.PhotoLibrary;
_callback = callback;
parent.PresentModalViewController(picker, true);
}
public void TakePicture()
{
var rc = UIApplication.SharedApplication.KeyWindow.RootViewController;
TakePicture(rc, (obj) =>
{
var photo = obj.ValueForKey(
new NSString("UIImagePickerControllerOriginalImage")) as UIImage;
var documentsDirectory =
Environment.GetFolderPath(Environment.SpecialFolder.Personal);
// hardcoded filename, overwritten each time
string jpgFilename = System.IO.Path.Combine(documentsDirectory,
"Photo.jpg");
NSData imgData = photo.AsJPEG();
NSError err = null;
if (imgData.Save(jpgFilename, false, out err))
{
Console.WriteLine("saved as " + jpgFilename);
}
else
{
Console.WriteLine("NOT saved as " +
jpgFilename + " because" + err.LocalizedDescription);
}
});
}
}
}
With this code after about 30 photos, the app crashes. The only difference is with this code I can receive some alert from ReceiveMemoryWarning. If you have an interest, I updated the code on GitHub.

BackgroundTaskRegistration trigger property is null

Hi want to receive push notifications on background task for that i have created Portable library here is my Background task class
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml.Linq;
using Windows.ApplicationModel.Background;
using Windows.Data.Xml.Dom;
using Windows.Networking.PushNotifications;
using Windows.Storage;
using Windows.UI.Notifications;
namespace BackgroundTask
{
public sealed class NotificationTask : IBackgroundTask
{
public void Run(IBackgroundTaskInstance taskInstance)
{
// Get the background task details
ApplicationDataContainer settings = ApplicationData.Current.LocalSettings;
string taskName = taskInstance.Task.Name;
Debug.WriteLine("Background " + taskName + " starting...");
// Store the content received from the notification so it can be retrieved from the UI.
ToastNotification notification = (ToastNotification )taskInstance.TriggerDetails;
settings.Values[taskName] = notification.Content;
NotificationTask.AddTostNotification(notification.Content);
Debug.WriteLine("Background " + taskName + " completed!");
}
private static void AddTostNotification(String xmlDocument)
{
List<string> messageSection = NotificationTask.GetMessageAndLandingPage(xmlDocument, "toast");
if (messageSection == null) { return; }
ToastTemplateType toastTemplate = ToastTemplateType.ToastText01;
XmlDocument toastXml = ToastNotificationManager.GetTemplateContent(toastTemplate);
XmlNodeList toastTextElements = toastXml.GetElementsByTagName("text");
toastTextElements[0].AppendChild(toastXml.CreateTextNode(messageSection[0]));
// toastTextElements[1].AppendChild(toastXml.CreateTextNode(message));
IXmlNode toastNode = toastXml.SelectSingleNode("/toast");
((XmlElement)toastNode).SetAttribute("launch", messageSection[1]);
XmlElement audio = toastXml.CreateElement("audio");
audio.SetAttribute("src", "ms-appx:///Assets/Play-Guitar.wav");
//audio.SetAttribute("loop", "true");
toastNode.AppendChild(audio);
//launch tost immediatly
ToastNotification toast = new ToastNotification(toastXml);
ToastNotificationManager.CreateToastNotifier().Show(toast);
}
Here i am registering Task
internal async void InitChannel()
{
// Applications must have lock screen privileges in order to receive raw notifications
BackgroundAccessStatus backgroundStatus = await BackgroundExecutionManager.RequestAccessAsync();
// Make sure the user allowed privileges
if (backgroundStatus != BackgroundAccessStatus.Denied && backgroundStatus != BackgroundAccessStatus.Unspecified)
{
Windows.Storage.ApplicationDataContainer roamingSettings = Windows.Storage.ApplicationData.Current.LocalSettings;
try
{
var channel = await PushNotificationChannelManager.CreatePushNotificationChannelForApplicationAsync();
if (channel != null)
{
roamingSettings.Values["ExistingPushChannel"] = channel.Uri;
dispatcher = Windows.UI.Core.CoreWindow.GetForCurrentThread().Dispatcher;
channel.PushNotificationReceived += OnPushNotificationReceived;
UnregisterBackgroundTask();
RegisterBackgroundTask();
}
else
{
roamingSettings.Values["ExistingPushChannel"] = "Failed to create channel";
}
}
catch
{
roamingSettings.Values["ExistingPushChannel"] = "Failed to create channel";
}
}
}
private void RegisterBackgroundTask()
{
BackgroundTaskBuilder taskBuilder = new BackgroundTaskBuilder();
PushNotificationTrigger trigger = new PushNotificationTrigger();
taskBuilder.SetTrigger(trigger);
// Background tasks must live in separate DLL, and be included in the package manifest
// Also, make sure that your main application project includes a reference to this DLL
taskBuilder.TaskEntryPoint = "BackgroundTask.NotificationTask";
taskBuilder.Name = "PlaypushNotification";
try
{
BackgroundTaskRegistration task = taskBuilder.Register();
task.Completed += BackgroundTaskCompleted;
}
catch
{
UnregisterBackgroundTask();
}
}
private bool UnregisterBackgroundTask()
{
foreach (var iter in BackgroundTaskRegistration.AllTasks)
{
IBackgroundTaskRegistration task = iter.Value;
if (task.Name == "PlaypushNotification")
{
task.Unregister(true);
return true;
}
}
return false;
}
In my Manifest file
<Extensions>
<Extension Category="windows.backgroundTasks" EntryPoint="BackgroundTask.NotificationTask">
<BackgroundTasks>
<Task Type="pushNotification" />
</BackgroundTasks>
</Extension>
</Extensions>
PushNotification Trigger is not firing, when i debug i found that trigger property of BackgroundTaskRegistration is null. what is the issue? What wrong is going here?

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