Interface article sample code

gistfile1.cs

    class PerishableItem
    {
        public string Name { get; set; }
        public double Price { get; set; }
        public double UnitPrice { get; set; }
        public uint SKU { get; set; }
        public DateTime SellByDate { get; set; }
        public DateTime ExpirationDate { get; set; }
        protected delegate void ExpiredItemHandler(object sender,ExpiredItemEventArgs e);
        public event ExpiredItemHandler Expired;

        protected void OnExpired(object item, ExpiredItemEventArgs eArgs)
        {
            if (this.Expired != null)
            {
                Expired(item, eArgs);
            }
        }

    }

    class NonPerishableItem
    {
        string Name { get; set; }
        double Price { get; set; }
        double UnitPrice { get; set; }
        uint SKU { get; set; }
    }

    class Scanner
    {
        public void Scan(PerishableItem item)
        {
            ///TODO: Update the inventory database using the product's SKU
            ///TODO: Add the price of this item to the order subtotal
        }

        public void Scan(NonPerishableItem item)
        {
            ///TODO: Update the inventory database using the product's SKU
            ///TODO: Add the price of this item to the order subtotal
        }

        public void CancelScan(PerishableItem item)
        {
            ///TODO: Update the inventory database using the product's SKU
            ///TODO: Subtract the price of this item from the order subtotal
        }

        public void CancelScan(NonPerishableItem item)
        {
            ///TODO: Update the inventory database using the product's SKU
            ///TODO: Subtract the price of this item from the order subtotal
        }
    }