Run new SMS received background events

The Mobile Broadband SMS platform provides separate system events for new SMS data that is received, depending on whether it’s an administrative SMS notification from a mobile network operator or a general SMS message. The background system event for a new administrative SMS notification that is received from a mobile network operator is only accessible by a mobile broadband app.

Apps must have already received user consent to use SMS to read new received SMS messages in a background tasks. Apps cannot read the contents of a new received SMS message from a background task if they are accessing SMS for the first time, because the app cannot trigger the system SMS device consent prompt from a background task.

The following code examples demonstrate a background task that is designed to run when a new SMS message is received.

C# background task code

namespace SmsBackgroundSample
{
  public sealed class SmsBackgroundTask : IBackgroundTask
  { 
    // The Run method is the entry point of a background task.

    public void Run(IBackgroundTaskInstance taskInstance)
    {
      // Associate a cancellation handler with the background task.

      taskInstance.Canceled += new BackgroundTaskCanceledEventHandler(OnCanceled);

      ManualResetEvent manualEventWaiter = new ManualResetEvent(false);
      manualEventWaiter.Reset();

      // Do the background task activity.

      DisplayToastAsync(taskInstance, manualEventWaiter);

      // Wait until the async operation is done. We need to do this else the background process will exit.
      manualEventWaiter.WaitOne(5000);

            Debug.Print("Background " + taskInstance.Task.Name + (" process ran"));

  }

  async void DisplayToastAsync(IBackgroundTaskInstance taskInstance, ManualResetEvent manualEventWaiter)
  {
    SmsReceivedEventDetails smsDetails = (SmsReceivedEventDetails)taskInstance.TriggerDetails;
    SmsBinaryMessage smsEncodedmsg = (SmsBinaryMessage) smsDetails.BinaryMessageMessage;
    SmsTextMessage smsTextMessage = Windows.Devices.Sms.SmsTextMessage.FromBinaryMessage(smsEncodedmsg);

    XmlDocument toastXml = ToastNotificationManager.GetTemplateContent(ToastTemplateType.ToastText02);
    XmlNodeList stringElements = toastXml.GetElementsByTagName("text");

    stringElements.Item(0).AppendChild(toastXml.CreateTextNode(smsTextMessage.From));
    stringElements.Item(1).AppendChild(toastXml.CreateTextNode(smsTextMessage.Body));

    ToastNotification notification = new ToastNotification(toastXml);
    ToastNotificationManager.CreateToastNotifier().Show(notification);

    manualEventWaiter.Set();
  }

}

JavaScript app code to register background task

var triggerAway = new Windows.ApplicationModel.Background.SystemTrigger(Windows.ApplicationModel.Background.SystemTriggerType.smsReceived, false);
var builderAway = new Windows.ApplicationModel.Background.BackgroundTaskBuilder();

builderAway.setTrigger(triggerAway);
builderAway.taskEntryPoint = "HelloWorldBackground.BackgroundTask1";
builderAway.name = "Sms";

var taskAway = builderAway.register();
taskAway.addEventListener("progress", new ProgressHandler(taskAway).onProgress);
taskAway.addEventListener("completed", new CompleteHandler(taskAway).onCompleted);

Related topics

Developing SMS apps