private void Delete_OnClick(object sender, RoutedEventArgs e) { if (_selectedFile != null) { _contentManager.DeleteContentFile(_imagesCache[_selectedFile.Name], (comboBox.SelectedItem as Lesson).ID); Files.Children.Remove(_selectedFile); _imagesCache.Remove(_selectedFile.Name); _selectedFile = null; _saved = false; Save.IsEnabled = true; DisableContentFileInfo(); DisableQuizInfo(); } }