public RadioEditorViewModel(IEditorViewModelFactory editorFactory) { _editorFactory = editorFactory; Title = "RadioButton Control"; AddChoiceCommand = new DelegateCommand(AddChoice, () => true); RemoveChoiceCommand = new DelegateCommand <ChoiceEditorViewModel>(choice => Choices.Remove(choice), choice => Choices.IndexOf(choice) > 0); Choices.CollectionChanged += (sender, args) => OnUpdateSnippet(); AddChoice(); }