// Конструктор модели представления
public GroupListViewModel(StudentHostelContext context) : base(context)
{
GetData();
if (GroupList == null)
{
CurrentGroup = null;
}
else if (GroupList.Count == 0)
{
CurrentGroup = null;
}
else
{
CurrentGroup = GroupList.First();
}
// Инициализация команд
AddCommand = new Command(Add, () => { return(!(IsAdding || IsEditing) && context != null); });
EditCommand = new Command(Edit, () => { return(!(IsAdding || IsEditing) && context != null); });
SaveCommand = new Command(SaveChanges, () => { return((IsAdding || IsEditing) && context != null); });
DeleteCommand = new Command(Delete, () => { return(!(IsAdding || IsEditing) && context != null); });
CancelCommand = new Command(DiscardChanges, () => { return((IsAdding || IsEditing) && context != null); });
}