C# 我已经附加了足够的代码，这样你现在就可以计算出程序的jist了。主方法还有4个“开关”部分。老实说，我知道这是惊人的实施，但这是一个任务，我一直在努力，所以我只是想确保我至少可以得到一个工作计划，这样我就可以真正通过。基本上，我已经构建了一个购物车，装载了

---

我已经附加了足够的代码，这样你现在就可以计算出程序的jist了。主方法还有4个“开关”部分。老实说，我知道这是惊人的实施，但这是一个任务，我一直在努力，所以我只是想确保我至少可以得到一个工作计划，这样我就可以真正通过。基本上，我已经构建了一个购物车，装载了基于输入从XML文件中选择的产品。我想做的是把所有的switch“1”语句放到一个新类的方法中，以便创建一个新的“策略”，我将为剩下的部分提供更多信息

static void Main(string[] args)
    {
        // Below code loads the XML file and builds Product objects with LINQ

        XDocument XDoc = XDocument.Load("inventory.xml");
        IEnumerable<Product> products = from q in XDoc.Descendants("product")
            select new Product
                {
                    RecordNumber = Convert.ToInt32(q.Element("recordNumber").Value),
                    Name = q.Element("name").Value,
                    Stock = Convert.ToInt32(q.Element("stock").Value),
                    Price = Convert.ToInt32(q.Element("price").Value),
                    CartQuantity = 0,
                    CartPrice = 0
                 };

        // Builds one instance of the cart that will be used to hold products

        Cart ShoppingCart = new Cart();

        Console.WriteLine("WELCOME TO CONSOLE-BASED SHOPPING CART!");
        Start:
        Console.WriteLine("Following options are available: \n" +
        "1. Add an item to cart, \n" +
        "2. Remove an item from the cart, \n" +
        "3. View the cart \n" +
        "4. Checkout and Pay \n" +
        "5. Exit \n");
        String input = Console.ReadLine();

        Context context;

     public class Cart : System.Collections.IEnumerable
{
    //Cart class - one instance is created to hold all the user's items
    //Includes methods to add, remove and check if cart contains an item
    // Also includes enumerator

    private List<Product> items;
    public Cart()
    {
        items = new List<Product>();
    }

    public System.Collections.IEnumerator GetEnumerator()
    {
        for (int i = 0; i < items.Count; i++)
        {
            yield return items[i];
        }
    }

    public void AddItem(Product prod)
    {
            items.Add(prod); 
    }

    public void RemoveProduct(Product prod)
    {
        items.Remove(prod);
    }

    public int CartCount()
    {
        return items.Count();
    }

    public void WriteToConsole()
    {
        Console.WriteLine("{0,16} {1, 16} {2, 16} {3, 16}","Item No.", "Item", "Amount", "Price");
        int TotalCost = 0;      //Iterator below allows us to work out total price
        foreach (Product x in this)
        {
            Console.WriteLine("{0,16} {1, 16} {2, 16} {3, 16}", x.RecordNumber, x.Name, x.CartQuantity, x.CartPrice);
            TotalCost = TotalCost + x.CartPrice;
        }

        Console.WriteLine("");
        Console.WriteLine("Total Price: {0,54}", TotalCost);
    }

    public void Reset()
    {
        foreach (Product x in this)
        {
            this.RemoveProduct(x);
            x.CartQuantity = 0;
            x.CartPrice = 0;
        }
    }

     public class Product
{

    // Product class - objects are built using LINQ in main method

    public int RecordNumber { get; set; }
    public String Name { get; set; }
    public int Price { get; set; }
    public int Stock { get; set; }
    public int CartQuantity { get; set; } 
    public int CartPrice { get; set; }

    public Product() { }
}