protected async override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
// Only using CameraRoll repository for now
PhotoCollection.RegisterRepository(new CameraRollRepository());
var availableSourceIds = await PhotoCollection.GetAvailableImageRepositoriesAsync();
ViewModel = new PhotoCollectionViewModel(availableSourceIds[0]);
DataContext = ViewModel;
}