UIFIS/OUP/ClassMain.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace OUP
{
    class ClassMain : BaseViewModel
    {
        private ObservableCollection<Product> _products;
        private ObservableCollection<CashRegister> _cashRegisters;
        private RelayCommand _updateOpenWindow;

        private Product _selectedProduct;
        private CashRegister _cashRegister;
        private RelayCommand _update;
        public RelayCommand UpdateOpenWindow
        {
            get
            {
                return _updateOpenWindow ??
                    (_updateOpenWindow = new RelayCommand((x) =>
                    {
                        if (x is CashRegister xx)
                        {

                        }
                    }));
            }
        }

        public ObservableCollection<Product> Products
        {
            get
            {
                return _products;
            }
            set
            {
                _products = value;
                OnPropertyChanged();
            }
        }
        public Product SelectedProduct
        {
            get
            {
                return _selectedProduct;
            }
            set
            {
                _selectedProduct = value;
                OnPropertyChanged();
            }
        }
        public CashRegister SelectedCashRegister
        {
            get
            {
                return _cashRegister;
            }
            set
            {
                _cashRegister = value;
                OnPropertyChanged();
            }
        }

        public ObservableCollection<CashRegister> CashRegister
        {
            get
            {
                return _cashRegisters;
            }
            set
            {
                _cashRegisters = value;
                OnPropertyChanged();
            }
        }

        private void LoadCollection()
        {
            Products.Clear();
            Products = new ObservableCollection<Product>(Helper.GetContext().Product);
        }

        public ClassMain()
        {
            _products = new ObservableCollection<Product>(Helper.GetContext().Product);
            _cashRegisters = new ObservableCollection<CashRegister>(Helper.GetContext().CashRegister);
        }
        public RelayCommand Update
        {
            get
            {
                return _update ??
                        (_update = new RelayCommand((x) =>
                        {
                            SelectedProduct.CashRegister = CashRegister;
                            Helper.GetContext().SaveChanges();
                            LoadCollection();


                        }));
            }
        }

    }
}