控制反轉(三)

控制反轉上層不依賴下層，而是依賴第三方依賴注入容器

上次的SimpleFactory就可以看做是第三方容器。學生student依賴SimpleFactory 而不直接依賴細節（Honor）

我們常用的第三方容器就是Unity,在VS中通過NuGet引入Unity的Dll,改造我們的Main方法

       

            static void Main(string[] args)
        {
            {
                BasePhone honor = SimpleFactory.CreatePhone();
                IPlayPhone student = SimpleFactory.CreateStudent();
                student.PlayPhone(honor);
                
                IUnityContainer unityContainer = new UnityContainer();
                unityContainer.RegisterType<IPlayPhone, Student>();
                var studentUnity = unityContainer.Resolve<IPlayPhone>();
                studentUnity.PlayPhone(honor);
                
                //Honor honor = new Honor();
                //Student student = new Student();
                //student.PlayPhone(honor);
                //student.PlayPhone(lumiaPhone);
                //student.PlayApplePhone(applePhone);
                //student.PlayGalaxy(galaxy);
                //student.PlayHonor(honor);
            }
            Console.ReadKey();
        }

再將代碼改造下增加IPerson，Iiphone，IGame

 public interface IPerson
    {
        Iiphone Iphone { get; set; }
        IGame Game { get; set; }
        
    }
  public class Student: BasePerson, IPerson
    {
        [Dependency]
        public Iiphone Iphone { get; set; }
        [Dependency]
        public IGame Game { get; set; }

    }
    public class Teacher: BasePerson, IPerson
    {
        [Dependency]
        public Iiphone Iphone { get; set; }
        [Dependency]
        public IGame Game { get; set; }
    }

 public interface Iiphone
    {
       void UsePhone();
    }
     
     public class Galaxy:BasePhone, Iiphone
    {
        public override void System()
        {
            Console.WriteLine("ANDROID");
        }
        public void UsePhone()
        {
            Console.WriteLine("Galaxy");
        }
    }

  public interface IGame
    {
        void Game();
    }
     public class SgsGame:IGame
    {
        public void Game()
        {
            Console.WriteLine("play 三國殺Game");
        }
    }
     public class LolGame:IGame
    {
        public void Game()
        {
            Console.WriteLine("Play LoLGame");
        }
    }
    
    
     static void Main(string[] args)
        {
            {
               

                IUnityContainer unityContainer = new UnityContainer();
              
                unityContainer.RegisterType<IPerson, Teacher>();
                unityContainer.RegisterType<Iiphone, Galaxy>();
                unityContainer.RegisterType<IGame, SgsGame>();
              
                var studentUnity = unityContainer.Resolve<IPerson>();
                studentUnity.Iphone.UsePhone();
                studentUnity.Game.Game();
            }

這裏用的是依賴注入中的屬性注入，屬性注入在構造函數注入之後執行，而且需要增加[Dependency]這個特性，並且需要添加using Microsoft.Practices.Unity;的引用，所以大部分時候都用構造函數注入更方便， 還有方法注入項目中用的很少，在方法上加[InjectionMethod]特性

unity提供更靈活的用配置文件註冊的方法 在項目配置文件增加

  <configSections>
    <section name="unity" type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection, Microsoft.Practices.Unity.Configuration"/>
  </configSections>
  <unity>
    <containers>
      <container name="defaultContainer">
        <register type="Abstract.IPerson,Abstract" mapTo="Abstract.Teacher, Abstract"/>
        <register type="Abstract.Iiphone,Abstract" mapTo="Abstract.Galaxy, Abstract"/>
        <register type="Abstract.IGame,Abstract" mapTo="Abstract.SgsGame, Abstract"/>
      </container>
    </containers>
  </unity>

則Main函數修改

 static void Main(string[] args)
        {
            {
                IUnityContainer unityContainer = new UnityContainer();
                UnityConfigurationSection configuration = (UnityConfigurationSection)ConfigurationManager.GetSection(UnityConfigurationSection.SectionName);
                configuration.Configure(unityContainer, "defaultContainer");
                
                var studentUnity = unityContainer.Resolve<IPerson>();
                studentUnity.OutputIdentity();
                studentUnity.Iphone.UsePhone();
                studentUnity.Game.Game();
            }
            Console.ReadKey();
        }