c# windows 10 raw notification when app is CLOSED

Question

I am developing a Windows 10 UWP application and I have a problem with raw notification sending and handling.

I am sending the notification from a server written in php, and when app is open I can receive the sent raw notification. Below is the template of my notification:

           <toast launch='args'>
                <visual>
                    <binding template = 'ToastGeneric'>
                         <text> başlık </text>
                         <text> Açıklama </text>
                        </binding>
                    </visual>
            </toast> 

I sent the template above as a raw notification.

Also, I am using the method below as backgroundtask

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.
        RawNotification notification = (RawNotification)taskInstance.TriggerDetails;
        settings.Values[taskName] = notification.Content;
        Windows.Data.Xml.Dom.XmlDocument doc = new XmlDocument();

        var toast = new ToastNotification(doc);
        var center = ToastNotificationManager.CreateToastNotifier();
        center.Show(toast);


        Debug.WriteLine("Background " + taskName + " completed!");
    }

I set the task entry point in appmanifest, I could not test it with debugger.

I register the background task with the code below:

 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 = SAMPLE_TASK_ENTRY_POINT;
        taskBuilder.Name = SAMPLE_TASK_NAME;

        try
        {
            BackgroundTaskRegistration task = taskBuilder.Register();
            task.Completed += BackgroundTaskCompleted;
        }
        catch (Exception ex)
        {
            // rootPage.NotifyUser("Registration error: " + ex.Message, NotifyType.ErrorMessage);
            UnregisterBackgroundTask();
        }
    }

Finally, my pushreceived event:

private async void OnPushNotificationReceived(PushNotificationChannel sender, PushNotificationReceivedEventArgs e)
    {
        if (e.NotificationType == PushNotificationType.Raw)
        {
            e.Cancel = false;

            Windows.Data.Xml.Dom.XmlDocument doc = new Windows.Data.Xml.Dom.XmlDocument();

            var t = @" <toast launch='args'>
                <visual>
                    <binding template = 'ToastGeneric'>
                         <text> başlık </text>
                         <text> Açıklama </text>
                        </binding>
                    </visual>
            </toast> ";

            doc.LoadXml(t);

            var toast = new ToastNotification(doc);
            var center = ToastNotificationManager.CreateToastNotifier();
            center.Show(toast);
        }
    }

the inside of the method is only for testing.

Now, I want to ask that what is wrong or missin in my structure? Any suggession, example or help is appreciated.

Thanks in advance.

Answer 1

Did you check in manifest Declarations that you have checked "Push notifications"?

Also you need at top the RegisterBackgroundTask method call

await BackgroundExecutionManager.RequestAccessAsync();

Here is documentation https://msdn.microsoft.com/pl-pl/library/hh700494.aspx where is important sentence "Requests that the app be permitted to run background tasks."

At the end check entry point and name of your background task