public EKvizWindowViewModel()
{
_answer = new Answer();
_course = new Course();
_question = new Question();
_quiz = new Quiz();
_modifiedQuiz = new Quiz();
_answers = new ObservableCollection<Answer>();
_quizes = new ObservableCollection<Quiz>();
_questions = new ObservableCollection<Question>();
_courses = new ObservableCollection<Course>();
_isSingleChoice = true;
_isMultipleChoice = false;
}
void ButtonRemoveAnswerExecute()
{
Answers.Remove(_answer);
_answer = null;
}