public void Execute(object parameter)
        {
            List <User> users = new List <User>();

            try
            {
                users = new List <User>(App.DB.UserRepository.GetAllData());
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            RentViewModel rentViewModel = new RentViewModel()
            {
                AllRents = App.DB.RentRepository.GetAllData()
            };

            try
            {
                rentViewModel.ClientViewModel = new ClientViewModel();
                var clients = App.DB.ClientRepository.GetAllData();
                rentViewModel.ClientViewModel.AllClients = clients;
            }
            catch (Exception)
            {
            }
            Book book = new Book();

            book = BookViewModel.SelectedBook;
            try
            {
                rentViewModel.CurrentRent = new Rent()
                {
                    Book          = book,
                    Client        = rentViewModel.ClientViewModel.SelectedClient,
                    RentDateTime  = DateTime.Now,
                    ExactDateTime = DateTime.Now,
                    Note          = "",
                    No            = 1,
                    Id            = 1,
                    User          = BookViewModel.CurrentUser
                };
                rentViewModel.CurrentRent.RealPrice = book.SalePrice;
                if (book.SalePrice > 10)
                {
                    rentViewModel.CurrentRent.PricePerDay = book.SalePrice / 10;
                }
                else
                {
                    rentViewModel.CurrentRent.PricePerDay = 1;
                }
            }
            catch (Exception)
            {
            }
            RentWindow rentWindow = new RentWindow(rentViewModel);

            rentWindow.ShowDialog();
        }
        private void AddRent_Click(object sender, RoutedEventArgs e)
        {
            var rent = new Rent();
            var add  = new RentWindow("Create new rent", rent, me);

            add.ShowDialog();

            what = "rents";
            SetDataGrid();
        }