I'm trying to implement geofencing in Windows phone 8.1. First I wanted to create a sample Project to understand how it Works, but i couldnt make it works. What I'm trying to achieve is basically, I'll set the coordinates and close the app by pressing back button and it will trigger a toast notification when the phone is in the area of interest.
I've created a blank Windows phone(silverlight) 8.1 Project(geofence_test_01) and added a Windows RT Component Project(BackgroundTask) into the same solution. Added a reference for BackgroundTask in the geofence_test_01 Project.
ID_CAP_LOCATION is enabled in the app manifest.
MainPage.xaml has only one button to start geofencing.
<Button Name="btnStart" Content="Start" Click="btnStart_Click"/>
In btnSave_Click, I call a method which creates the geofence and registers the background task.
private void btnStart_Click(object sender, RoutedEventArgs e)
{
Init_BackgroundGeofence();
registerBackgroundTask();
}
private async Task Init_BackgroundGeofence()
{
//----------------- Crating Geofence ---------------
var geofenceMonitor = GeofenceMonitor.Current;
var geoId = "building9";
var positionBuilding9 = new BasicGeoposition()
{
Latitude = 47.6397,
Longitude = -122.1289
};
var geofence = new Geofence(geoId, new Geocircle(positionBuilding9, 100),
MonitoredGeofenceStates.Entered | MonitoredGeofenceStates.Exited,
false, TimeSpan.FromSeconds(10));
geofenceMonitor.Geofences.Add(geofence);
}
private async Task registerBackgroundTask()
{
//----------------- Register Background Task ---------------
var backgroundAccessStatus =
await BackgroundExecutionManager.RequestAccessAsync();
var geofenceTaskBuilder = new BackgroundTaskBuilder
{
Name = "GeofenceBackgroundTask",
TaskEntryPoint = "BackgroundTask.GeofenceBackgroundTask"
};
var trigger = new LocationTrigger(LocationTriggerType.Geofence);
geofenceTaskBuilder.SetTrigger(trigger);
var geofenceTask = geofenceTaskBuilder.Register();
}
And finally, in BackgroundTask, I've the following code:
namespace BackgroundTask
{
public sealed class GeofenceBackGroundTask : IBackgroundTask
{
public void Run(IBackgroundTaskInstance taskInstance)
{
var geofenceMonitor = GeofenceMonitor.Current;
var geoReports = geofenceMonitor.ReadReports();
var geoId = "building9";
foreach (var geofenceStateChangeReport in geoReports)
{
var id = geofenceStateChangeReport.Geofence.Id;
var newState = geofenceStateChangeReport.NewState;
if (id == geoId && newState == GeofenceState.Entered)
{
//------ Call NotifyUser method when Entered -------
notifyUser();
}
}
}
private void notifyUser()
{
var toastTemplate = ToastTemplateType.ToastText02;
var toastXML = ToastNotificationManager.GetTemplateContent(toastTemplate);
var textElements = toastXML.GetElementsByTagName("text");
textElements[0].AppendChild(toastXML.CreateTextNode("You are in!"));
var toast = new ToastNotification(toastXML);
ToastNotificationManager.CreateToastNotifier().Show(toast);
}
}
}
I get no error when building and deploying this in the emulator. I set a breakpoint in the backgroundTask but I've not seen that part of code is called yet. It never hits the breakpoint. I test it by using Additional Tools of the emulator, in Location tab, by clicking somewhere in my geofence area on the map, waiting for a while, but it never hits the breakpoint. Hope somebody can tell me what i am missing here...
I've checked these following links to build this application:
http://www.jayway.com/2014/04/22/windows-phone-8-1-for-developers-geolocation-and-geofencing/
Geofence in the Background Windows Phone 8.1 (WinRT)
Toast notification & Geofence Windows Phone 8.1
http://java.dzone.com/articles/geofencing-windows-phone-81
Thanks
You can download the project here: https://drive.google.com/file/d/0B8Q_biJCWl4-QndYczR0cjNhNlE/view?usp=sharing
---- Some clues
Thanks to Romasz, I've checked the Lifecycle events and i see "no background tasks" even after registerBackgroundTask() is executed.... Apparently there is something wrong/missing in registerBackgroundTask() method.
