使用Facade模式更新库存、确认订单、采取打折、确认支付、完成支付、物流配送

Facade模式对外提供了统一的接口，而隐藏了内部细节。在网上购物的场景中，当点击提交订单按钮，与此订单相关的库存、订单确认、折扣、确认支付、完成支付、物流配送等都要做相应的动作。本篇尝试使用Facade模式，把这些类似工作者单元的动作隐藏到一类中，只要点击提交订单，余下的事情一步到位：

□ 关于库存

namespace ConsoleApplication1.Interfaces

{

    public interface IInventory

    {

        void Update(int productId);

    }

}



using System;

using ConsoleApplication1.Interfaces;



namespace ConsoleApplication1.Implements

{

    public class InventoryManager : IInventory

    {

        public void Update(int productId)

        {

            Console.WriteLine(string.Format("产品编号为{0}的库存已更新", productId));

        }

    }

}

 

□ 关于确认订单

namespace ConsoleApplication1.Interfaces

{

    public interface IOrderVerify

    {

        bool VerifyShippingAddress(int pinCode);

    }

}



using System;

using ConsoleApplication1.Interfaces;



namespace ConsoleApplication1.Implements

{

    public class OrderVerifyManager : IOrderVerify

    {

        public bool VerifyShippingAddress(int pinCode)

        {

            Console.WriteLine(string.Format("产品可被运输至{0}", pinCode));

            return true;

        }

    }

}

 

□ 关于打折

namespace ConsoleApplication1.Interfaces

{

    public interface ICosting

    {

        float ApplyDiscounts(float originalPrice, float discountPercent);

    }

}



using System;

using ConsoleApplication1.Interfaces;



namespace ConsoleApplication1.Implements

{

    public class CostManager : ICosting

    {

        public float ApplyDiscounts(float originalPrice, float discountPercent)

        {

            Console.WriteLine(string.Format("产品的原价为：{0}，采取的折扣为{1}%", originalPrice, discountPercent));

            return originalPrice - ((discountPercent/100)*originalPrice);

        }

    }

}

 

□ 关于确认支付和支付

namespace ConsoleApplication1.Interfaces

{

    public interface IPaymentGateway

    {

        bool VerifyCardDetails(string cardNo);

        bool ProcessPayment(string cardNo, float cost);

    }

}



using System;

using ConsoleApplication1.Interfaces;



namespace ConsoleApplication1.Implements

{

    public class PaymentGatewayManager : IPaymentGateway

    {

        public bool VerifyCardDetails(string cardNo)

        {

            Console.WriteLine(string.Format("卡号为{0}的卡可以被使用",cardNo));

            return true;

        }



        public bool ProcessPayment(string cardNo, float cost)

        {

            Console.WriteLine(string.Format("卡号为{0}的卡支付{0}元",cardNo, cost));

            return true;

        }

    }

}

□ 关于物流

namespace ConsoleApplication1.Interfaces

{

    public interface ILogistics

    {

        void ShipProduct(string productName, string shippingAddress);

    }

}



using System;

using ConsoleApplication1.Interfaces;



namespace ConsoleApplication1.Implements

{

    public class LogisticsManager : ILogistics

    {

        public void ShipProduct(string productName, string shippingAddress)

        {

            Console.WriteLine(string.Format("产品{0}准备发送至{1}", productName, shippingAddress));

        }

    }

}

 

□ 关于OrderDetails

using System;



namespace ConsoleApplication1.Model

{

    public class OrderDetails

    {

        public int ProductNo { get; set; }

        public string ProductName { get; set; }

        public string ProductDescription { get; set; }

        public float Price { get; set; }

        public float DiscountPercent { get; set; }

        public string Address1 { get; set; }

        public string Addres2 { get; set; }

        public int PinCode { get; set; }

        public string CardNo { get; set; }



        public OrderDetails(string productName, string prodDescription, float price,

            float discount, string address1, string address2,

            int pinCode, string cardNo)

        {

            this.ProductNo = new Random(1).Next(1, 100);

            this.ProductName = productName;

            this.ProductDescription = prodDescription;

            this.Price = price;

            this.DiscountPercent = discount;

            this.Address1 = address1;

            this.Addres2 = address2;

            this.PinCode = pinCode;

            this.CardNo = cardNo;

        }

    }

}

 

□ 体现Facade模式的类

using ConsoleApplication1.Implements;

using ConsoleApplication1.Interfaces;

using ConsoleApplication1.Model;



namespace ConsoleApplication1.Services

{

    public class OnlineShoppingFacade

    {

        IInventory inventory = new InventoryManager();

        IOrderVerify orderVerify = new OrderVerifyManager();

        ICosting costManager = new CostManager();

        IPaymentGateway paymentGateway = new PaymentGatewayManager();

        ILogistics logistics = new LogisticsManager();



        public void SubmitOrder(OrderDetails ordeerDetails)

        {

            inventory.Update(ordeerDetails.ProductNo);

            orderVerify.VerifyShippingAddress(ordeerDetails.PinCode);

            ordeerDetails.Price = costManager.ApplyDiscounts(ordeerDetails.Price, ordeerDetails.DiscountPercent);

            paymentGateway.VerifyCardDetails(ordeerDetails.CardNo);

            paymentGateway.ProcessPayment(ordeerDetails.CardNo, ordeerDetails.Price);

            logistics.ShipProduct(ordeerDetails.ProductName, string.Format("{0},{1} - {2}",ordeerDetails.Address1, ordeerDetails.Addres2,ordeerDetails.PinCode));

        }

    }

}

 

□ 客户端调用

using System;

using ConsoleApplication1.Model;

using ConsoleApplication1.Services;



namespace ConsoleApplication1

{

    class Program

    {

        static void Main(string[] args)

        {

            OrderDetails orderDetails = new OrderDetails("产品A",

                "清凉一夏",

                800,

                20,

                "山东省",

                "青岛市",

                1122,

                "888666999");



            OnlineShoppingFacade onlineShopping = new OnlineShoppingFacade();

            onlineShopping.SubmitOrder(orderDetails);



            Console.ReadKey();

        }

    }

}

参考资料：
Facade Design Pattern