protected override void OnNavigatedFrom(NavigationEventArgs e)
{
CoreWindow.GetForCurrentThread().KeyDown -= SearchPage_KeyDown;
Cancellation?.Cancel();
SearchResultList.RemoveHandler(PointerPressedEvent, PointerPressedEventHandler);
SelectionExtention.Dispose();
SelectionExtention = null;
if (e.NavigationMode == NavigationMode.Back)
{
SearchResult.Clear();
}
}