private async void OnItemTapped(object sender, ItemTappedEventArgs e)
        {
            DBWord selectedWord = e.Item as DBWord;

            if (selectedWord != null)
            {
                WordPage page = new WordPage(_dictionaryService, selectedWord);
                await Navigation.PushAsync(page);
            }
        }
 private async void OnButtonClicked(object sender, EventArgs e)
 {
     WordPage page = new WordPage(_dictionaryService, null);
     await Navigation.PushAsync(page);
 }