Unity 依赖注入知识点

三种依赖注入方法，构造器注入、属性注入、方法注入

可以配置Config文件，来实现不用修改代码。需要先将接口与实体关联，然后使用时会自动加载对应实体。

namespace WeChatConsole
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            #region 构造器注入，需要在构造函数中传递抽象参数

            UnityContainer container = new UnityContainer();
            container.RegisterType<IWaterTool, Press2Water>(); //依赖注入
            //container.RegisterType<IWaterTool, Press2Water>(); //重复注入会替换
            IPeople people = container.Resolve<VillagePeople>(); //返回
            people.DrinkWater();
            #endregion

            #region 属性注入
            IPeople people2 = container.Resolve<Village2People>(); //返回
            people2.DrinkWater();
            #endregion

            #region 读取配置文件
            UnityContainer container2 = new UnityContainer();
            UnityConfigurationSection configuration = ConfigurationManager.GetSection(UnityConfigurationSection.SectionName) as UnityConfigurationSection;
            configuration.Configure(container2, "WeChatContatiner");
            IPeople people3 = container2.Resolve<Village2People>(); //返回
            people3.DrinkWater();
            #endregion

            Console.Read();
        }
    }
    //人
    interface IPeople
    {
        void DrinkWater();
    }
    //村民
    class VillagePeople : IPeople
    {
        IWaterTool _pw;
        public VillagePeople(IWaterTool pw)
        {
            _pw = pw;
        }
        public void DrinkWater()
        {
            Console.WriteLine(_pw.returnWater());
        }
    }
    class Village2People : IPeople
    {
        [Dependency] //属性注入模式
        public IWaterTool _pw { get; set; }

        [InjectionMethod] //方法注入模式
        public void DrinkWater()
        {
            Console.WriteLine(_pw.returnWater() + " 第二版");
        }
    }
    //水
    interface IWaterTool
    {
        string returnWater();
    }
    //压水井
    class PressWater : IWaterTool
    {
        public string returnWater()
        {
            return "压水井执行方法";
        }
    }
    class Press2Water : IWaterTool
    {
        public string returnWater()
        {
            return "压水井2执行方法";
        }
    }
}

配置文件如下：

<configSections>
    <section name="unity" type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection,Microsoft.Practices.Unity.Configuration" />
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6" />
  </startup>
  <unity>
    <container name="WeChatContatiner">
      <register type="WeChatConsole.IWaterTool,WeChatConsole" mapTo="WeChatConsole.Press2Water,WeChatConsole" />
    </container>
  </unity>

在看一个例子

public static class Program
    {
        public static void Main(string[] args)
        {
            IUnityContainer container = new UnityContainer();
            UnityConfigurationSection configuration = ConfigurationManager.GetSection(UnityConfigurationSection.SectionName) as UnityConfigurationSection;
            configuration.Configure(container, "defaultContainer");
            A a = container.Resolve<IA>() as A;
            if (a != null)
            {
                Console.WriteLine("a.B=" + a.B == null ? "Y" : "N");
                Console.WriteLine("a.C=" + a.C == null ? "Y" : "N");
                Console.WriteLine("a.D=" + a.D == null ? "Y" : "N");
            }
            Console.ReadKey();
        }
    }

    public interface IA { }
    public interface IB { }
    public interface IC { }
    public interface ID { }
    public class A : IA
    {
        public IB B { get; set; }

        [Dependency]
        public IC C { get; set; }

        public ID D { get; set; }

        public A(IB b)
        {
            this.B = b;
        }

        [InjectionMethod]
        public void Initialize(ID d)
        {
            this.D = d;
        }
    }
    public class B : IB { };
    public class C : IC { };
    public class D : ID { };

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <section name="unity" type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection,
             Microsoft.Practices.Unity.Configuration" />
  </configSections>
  <unity>
    <containers>
      <container name="defaultContainer">
        <register type="ConsoleApplication1.IA,ConsoleApplication1" mapTo="ConsoleApplication1.A,ConsoleApplication1" />
        <register type="ConsoleApplication1.IB,ConsoleApplication1" mapTo="ConsoleApplication1.B,ConsoleApplication1" />
        <register type="ConsoleApplication1.IC,ConsoleApplication1" mapTo="ConsoleApplication1.C,ConsoleApplication1" />
        <register type="ConsoleApplication1.ID,ConsoleApplication1" mapTo="ConsoleApplication1.D,ConsoleApplication1" />
      </container>
    </containers>
  </unity>
</configuration> 

MVC

在MVC框架下使用Unity，需要在引入Unity.MVC 这个Nuget包

然后在Global.asax.cs 中，注入依赖

UnityContainer unityContainer = new UnityContainer();
            unityContainer.RegisterType<IEmployeeRepository, EmployeeRepository>();
            DependencyResolver.SetResolver(new UnityDependencyResolver(unityContainer));

此时，在控制器中，就可以使用构造器注入、属性注入、方法注入了

BuildUp

可以给对象进行注入显示注入，调用此方法，我们的对象就包含注入的方法了。

 IUnityContainer container = new UnityContainer();
            UnityConfigurationSection configuration = ConfigurationManager.GetSection(UnityConfigurationSection.SectionName) as UnityConfigurationSection;
            configuration.Configure(container, "defaultContainer");
            Program pro = new Program();
            container.BuildUp(pro);
            pro.HttpClient();

protected void Application_PreRequestHandlerExecute(object sender,EventArgs e)
{
Page handler = HttpContext.Current.Handler as Page;
if(handler != null){
  IUnityContainer container = 实体;
  if(container != null){
     container.BuildUp(handler.GetType(),handler);
  }
}
}