private void BtnOpenStudentView(object sender, RoutedEventArgs e)
{
StudentView view = new StudentView();
view.Closing += StudentView_Closing;
view.ShowDialog();
}
public void Execute(object parameter)
{
StudentViewModel studentViewModel = new StudentViewModel();
studentViewModel.AllStudents = App.DB.StudentRepository.GetAllData();
StudentView studentView = new StudentView(studentViewModel);
studentView.ShowDialog();
}