IoC using Unity 3.5 with Generic type

.NET   IOC    Design Pattern   Unity

▌背景

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Unity Application Block (Unity)在泛型的使用方式。 以下分別介紹在Run-time(程式碼注入)以及Design-time(由設定檔注入)的方式。

▌環境

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l   Windows 7 pro l   IIS Express 7.5 l   Visual Studio 2013 update4 (C#) l   Unity Application Block (Unity) 3.5.1404

▌實作

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▋Create Model as “parameter” in IOC constructor. l   A class which will be used as a parameter. public class Customer {         public String Name { get; set; }         public String Sex { get; set; }         public String PhoneNumber { get; set; } } l   A enum class which will be used as a parameter. public enum Service {         [EnumAttr(Desc = "打蠟")]         Wax,         [EnumAttr(Desc = "洗車")]         Wash,         [EnumAttr(Desc = "內裝清理")]         Clean } ▋Interface public interface IPainter<T> {    void Paint(T car); } ▋Class l   RedPainter : No constructor public class RedPainter<T> : IPainter<T> where T: ICar     {         public void Paint(T car)         {             car.Color = Color.Red;             Debug.WriteLine("已烤漆為紅色!");         }     } l   BluePainter : Constructor with String parameter public class BluePainter<T> : IPainter<T> where T: ICar     {         private String _extraMsg = String.Empty;         public BluePainter(String extraMsg)         {             this._extraMsg = extraMsg;         }         public void Paint(T car)         {             car.Color = Color.Blue;             Debug.WriteLine(String.Format("已烤漆為藍色! ({0}) ", this._extraMsg));         }     } l   SilverPainter : Constructor with Enum parameter public class SilverPainter<T> : IPainter<T> where T: ICar     {         private Service _service;         public SilverPainter(Service service)         {             this._service = service;         }         public void Paint(T car)         {             car.Color = Color.Blue;             Debug.WriteLine(String.Format("已烤漆為銀色! ({0}) ",                 String.Concat("額外服務:",this._service.GetAttr().Desc)));         }     } l   BlackPainter : Constructor with Json parameter (Deserize to an object later) public class BlackPainter<T> : IPainter<T> where T: ICar     {         private Customer _customer;         public BlackPainter(String jsonStr)         {             //Deserialize             using (var deserializer = new Adaman.Infra.Serializer.JsonSerializer())             {                 this._customer = deserializer.DeserializeToObject<Customer>(jsonStr);             }         }         public void Paint(T car)         {             car.Color = Color.Blue;             Debug.WriteLine(String.Format("已烤漆為黑色! ({0},{1},{2}) ",                 this._customer.Name,                 this._customer.Sex,                 this._customer.PhoneNumber));         }     }

▋Run-time DI

IPainter<ICar> painter = null; IUnityContainer container = new UnityContainer(); //注入容器 … container.RegisterType<IPainter<ICar>, BluePainter<ICar>>(                 new InjectionConstructor("金額 10,000")); //取得容器的组件 painter = container.Resolve<IPainter<ICar>>(); //使用注入的物件 ICar focus = new Focus(); painter.Paint(focus); //GC container.Dispose();

執行結果 :

已烤漆為藍色! (金額 10,000)

▋Create Model as “parameter” in IOC constructor. l   A class which will be used as a parameter. public class Customer {         public String Name { get; set; }         public String Sex { get; set; }         public String PhoneNumber { get; set; } } l   A enum class which will be used as a parameter. public enum Service {         [EnumAttr(Desc = "打蠟")]         Wax,         [EnumAttr(Desc = "洗車")]         Wash,         [EnumAttr(Desc = "內裝清理")]         Clean } ▋Interface public interface IPainter<T> {    void Paint(T car); } ▋Class l   RedPainter : No constructor public class RedPainter<T> : IPainter<T> where T: ICar     {         public void Paint(T car)         {             car.Color = Color.Red;             Debug.WriteLine("已烤漆為紅色!");         }     } l   BluePainter : Constructor with String parameter public class BluePainter<T> : IPainter<T> where T: ICar     {         private String _extraMsg = String.Empty;         public BluePainter(String extraMsg)         {             this._extraMsg = extraMsg;         }         public void Paint(T car)         {             car.Color = Color.Blue;             Debug.WriteLine(String.Format("已烤漆為藍色! ({0}) ", this._extraMsg));         }     } l   SilverPainter : Constructor with Enum parameter public class SilverPainter<T> : IPainter<T> where T: ICar     {         private Service _service;         public SilverPainter(Service service)         {             this._service = service;         }         public void Paint(T car)         {             car.Color = Color.Blue;             Debug.WriteLine(String.Format("已烤漆為銀色! ({0}) ",                 String.Concat("額外服務:",this._service.GetAttr().Desc)));         }     } l   BlackPainter : Constructor with Json parameter (Deserize to an object later) public class BlackPainter<T> : IPainter<T> where T: ICar     {         private Customer _customer;         public BlackPainter(String jsonStr)         {             //Deserialize             using (var deserializer = new Adaman.Infra.Serializer.JsonSerializer())             {                 this._customer = deserializer.DeserializeToObject<Customer>(jsonStr);             }         }         public void Paint(T car)         {             car.Color = Color.Blue;             Debug.WriteLine(String.Format("已烤漆為黑色! ({0},{1},{2}) ",                 this._customer.Name,                 this._customer.Sex,                 this._customer.PhoneNumber));         }     }

▋Run-time DI

IPainter<ICar> painter = null; IUnityContainer container = new UnityContainer(); //注入容器 … container.RegisterType<IPainter<ICar>, BluePainter<ICar>>(                 new InjectionConstructor("金額 10,000")); //取得容器的组件 painter = container.Resolve<IPainter<ICar>>(); //使用注入的物件 ICar focus = new Focus(); painter.Paint(focus); //GC container.Dispose();

執行結果 :

已烤漆為藍色! (金額 10,000)

▋Design-time DI

l   主程式

using Microsoft.Practices.Unity.Configuration; // Must for LoadConfiguration method! IPainter<ICar> painter = null; IUnityContainer container = new UnityContainer(); //從Config注入容器 … container.LoadConfiguration("UnityCfg_Painter"); //取得IFile容器的组件 painter = container.Resolve<IPainter<ICar>>(); ICar focus = new Focus(); painter.Paint(focus); //GC container.Dispose();

l   設定檔 : 注入 RedPainter : No constructor

在設定Config前，必須知道下面三個型別的完整型別名稱：

1.  Generic interface

2.  Generic class (which implement 1.)

3.  Generic Data type

在此範例對應為：

1.  IPainter<>

2.  RedPainter<>

3.  ICar

只要使用以下程式碼即可知道完整型別名稱…

Debug.WriteLine(typeof(IPainter<>).AssemblyQualifiedName);

Output :

DI_Generic.Strategy.IPainter`1, DI_Generic, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null

接著便可以開始設定Config，

<configuration>   <configSections>     <section name="unity" type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection, Microsoft.Practices.Unity.Configuration" />   </configSections>       <unity>     <assembly name="DPLib" />     <assembly name="DI_Generic" />     <namespace name="DPLib" />     <namespace name="DI_Generic.Strategy" />     <alias alias="CarInterface" type="DPLib.ICar, DPLib" />     <alias alias="PainterInterface" type="DI_Generic.Strategy.IPainter`1, DI_Generic" />     <alias alias="PainterClass" type="DI_Generic.Strategy.RedPainter`1, DI_Generic" />     <container name="UnityCfg_Painter">       <register type="PainterInterface[CarInterface]" mapTo="PainterClass[CarInterface]">       </register>     </container>       </unity>  </configuration>

PS. 注意在Register type時的寫法，必須用”[]”包住Generic Data type：

<register type="PainterInterface[CarInterface]"

mapTo="PainterClass[CarInterface]" />

執行結果：

已烤漆為紅色!

l   設定檔 : 注入 BluePainter : Constructor with String parameter

在<Register> tag裡加入 <constructor> & <param>，注意名稱必須和實際的參數名稱相同。

<configuration>   <unity>     <alias alias="CarInterface" type="DPLib.ICar, DPLib" />     <alias alias="PainterInterface" type="DI_Generic.Strategy.IPainter`1, DI_Generic" />     <alias alias="PainterClass" type="DI_Generic.Strategy.BluePainter`1, DI_Generic" />     <container name="UnityCfg_Painter">       <register type="PainterInterface[CarInterface]" mapTo="PainterClass[CarInterface]"> <constructor>           <param name="extraMsg" value="客戶下午兩點取車"/>         </constructor>       </register>     </container>       </unity>  </configuration>

執行結果：

已烤漆為藍色! (客戶下午兩點取車)

l   設定檔 : 注入 SilverPainter : Constructor with Enum parameter

參數為列舉型別時，必須手動指定參數的型別，而value的設定方式：

Ex1. value="Wax" => Service.Wax

Ex2. value="Wash" => Service.Wash

Ex3. value="Clean" => Service.Clean

<configuration>   <unity>     <alias alias="CarInterface" type="DPLib.ICar, DPLib" />     <alias alias="PainterInterface" type="DI_Generic.Strategy.IPainter`1, DI_Generic" />     <alias alias="PainterClass" type="DI_Generic.Strategy.SilverPainter`1, DI_Generic" />     <container name="UnityCfg_Painter">       <register type="PainterInterface[CarInterface]" mapTo="PainterClass[CarInterface]"> <constructor>           <param name="service" value="Wax" type="DI_Generic.Service, DI_Generic"/>          </constructor>       </register>     </container>       </unity>  </configuration>

執行結果：

已烤漆為銀色! (額外服務:打蠟)

l   設定檔 : 注入 BlackPainter :

Constructor with Json parameter (Deserize to an object later)

如果注入的class的建構參數為一物件，折衷的方式是帶入JSON，再deserialize成物件。

但是JSON中的雙引號在放進Config時，必須改成HTML字元：&quot;

<configuration>   <unity>     <alias alias="CarInterface" type="DPLib.ICar, DPLib" />     <alias alias="PainterInterface" type="DI_Generic.Strategy.IPainter`1, DI_Generic" />     <alias alias="PainterClass" type="DI_Generic.Strategy.BlackPainter`1, DI_Generic" />     <container name="UnityCfg_Painter">       <register type="PainterInterface[CarInterface]" mapTo="PainterClass[CarInterface]"> <constructor>           <param name="jsonStr" value="{&quot;Name&quot;: &quot;JB&quot;,&quot;Sex&quot;: &quot;男&quot;,&quot;PhoneNumber&quot;: &quot;0933123XXX&quot;}" />         </constructor>       </register>     </container>       </unity>  </configuration>

執行結果：

已烤漆為黑色! (JB,男,0933123XXX)

▌Conclusion

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在寫IOC程式碼時，一開始會花比較多時間，但是完成後，對於程式的彈性和可擴展性都加了不少分。

▌Reference

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l   MSDN : The Unity Configuration Schema l   Using Unity for IoC and DI