protected override void OnNavigatedTo(NavigationEventArgs e)
{
this._navigationHelper.OnNavigatedTo(e);
_skipNextSelectionChanged = true;
ListBoxItems.ItemTemplate = ListPicker.PageItemTemplate;
ListBoxItems.ItemsSource = null;
_skipNextSelectionChanged = true;
ListBoxItems.ItemsSource = ListPicker.NullItemCollection;
ListBoxItems.SelectedItem = ListPicker.GetItemWithNullItem();
base.OnNavigatedTo(e);
}