public void SetDeviceLocationOptions( 
   MapDeviceLocationOptions options
)

{
    //Note: Run within a QueuedTask
    //Check there is a source first...
    if (DeviceLocationService.Instance.GetSource() == null)
        //Setting DeviceLocationOptions w/ no Device Location Source
        //Will throw an InvalidOperationException
        return;

    if (!MapDeviceLocationService.Instance.IsDeviceLocationEnabled)
        //Setting DeviceLocationOptions w/ no Device Location Enabled
        //Will throw an InvalidOperationException
        return;

    MapDeviceLocationService.Instance.SetDeviceLocationOptions(
      new MapDeviceLocationOptions()
      {
          DeviceLocationVisibility = true,
          NavigationMode = MappingDeviceLocationNavigationMode.KeepAtCenter,
          TrackUpNavigation = true
      });
}

{
    // Get the MapDeviceLocationOptions currently used by the MapDeviceLocationService

    var currentOptions = MapDeviceLocationService.Instance.GetDeviceLocationOptions();
    if (currentOptions == null)
        return;
    // Set the device location visibility on the map to true
    currentOptions.DeviceLocationVisibility = true;
    //Set the navigation mode to keep the device location at the center of the map
    currentOptions.NavigationMode = MappingDeviceLocationNavigationMode.KeepAtCenter;
    //Note: Run within a QueuedTask
    //Sets the MapDeviceLocationOptions to be updates with these values
    MapDeviceLocationService.Instance.SetDeviceLocationOptions(currentOptions);
}