【设计模式】工厂方法（FactoryMethod）模式

看不见PPT的请自行解决DNS污染问题。

相关类的代码：

1 namespace FactoryPatternConsole.Model
2 {
3     public class Address
4     {
5         public string CountryCode { get; set; }
6     }
7 }

Address

 1 namespace FactoryPatternConsole.Model
 2 {
 3     public class Order
 4     {
 5         public decimal TotalCost { get; set; }
 6         public decimal WeightInKG { get; set; }
 7         public string CourierTrackingId { get; set; }
 8         public Address DispatchAddress { get; set; }
 9     }
10 }

Order

1 namespace FactoryPatternConsole.Model
2 {
3     public interface IShippingCourier
4     {
5         string GenerateConsignmentLabelFor(Address address);
6     }
7 }

IShippingCourier

 1 namespace FactoryPatternConsole.Model
 2 {
 3     public class DHL : IShippingCourier
 4     {
 5         public string GenerateConsignmentLabelFor(Address address)
 6         {
 7             return "DHL-XXXX-XXXX-XXXX";
 8         }
 9     }
10 }

DHL

 1 namespace FactoryPatternConsole.Model
 2 {
 3     public class RoyalMail:IShippingCourier
 4     {
 5         public string GenerateConsignmentLabelFor(Address address)
 6         {
 7             return "RM-XXXX-XXXX-XXXX";
 8         }
 9     }
10 }

RoyalMail

 1 using FactoryPatternConsole.Model;
 2 
 3 namespace FactoryPatternConsole.Factory
 4 {
 5     public static class UKShippingCourierFactory
 6     {
 7         public static IShippingCourier CreateShippingCourier(Order order)
 8         {
 9             if (order.TotalCost > 100 || order.WeightInKG > 5)
10             {
11                 return new DHL();
12             }
13             else
14             {
15                 return new RoyalMail();
16             }
17         }
18     }
19 }

UKShippingCourierFactory

 1 using FactoryPatternConsole.Factory;
 2 using FactoryPatternConsole.Model;
 3 
 4 namespace FactoryPatternConsole.Service
 5 {
 6     public class OrderService
 7     {
 8         public void Dispatch(Order order)
 9         {
10             IShippingCourier shippingCourier = UKShippingCourierFactory.CreateShippingCourier(order);
11 
12             order.CourierTrackingId = shippingCourier.GenerateConsignmentLabelFor(order.DispatchAddress);
13         }
14     }
15 }

OrderService

测试用代码：

 1 using FactoryPatternConsole.Model;
 2 using FactoryPatternConsole.Service;
 3 using System;
 4 
 5 namespace FactoryPatternConsole
 6 {
 7     class Program
 8     {
 9         static void Main(string[] args)
10         {
11             OrderService service = new OrderService();
12             foreach (Order order in GetOrders())
13             {
14                 service.Dispatch(order);
15                 Console.WriteLine(string.Format("TotalCost:{0}, WeightInKG:{1}, CourierTrackingId:{2}",
16                     order.TotalCost, order.WeightInKG, order.CourierTrackingId));
17             }
18             Console.ReadLine();
19         }
20 
21         public static Order[] GetOrders()
22         {
23             return new Order[] {
24                 new Order() 
25                 { 
26                     TotalCost = 100,
27                     WeightInKG = 5,
28                     DispatchAddress = new Address() { CountryCode = "CN" },
29                 },
30                 new Order() 
31                 { 
32                     TotalCost = 100.1m,
33                     WeightInKG = 4,
34                     DispatchAddress = new Address() { CountryCode = "CN" },
35                 },
36                 new Order() 
37                 { 
38                     TotalCost = 100,
39                     WeightInKG = 5.1m,
40                     DispatchAddress = new Address() { CountryCode = "CN" },
41                 },
42             };
43         }
44     }
45 }

Program

执行结果：