我应该将 Unity 容器传递给我的依赖项吗？

Question

所以我有：

应用程序 A：需要 B 类（不同的程序集）

B 类：需要 C 类（同样，不同的程序集）

C 类：使用容器来解析各种对象，但容器的生命周期（及其解析的对象）应由成分根控制。

我想我明白这在大多数情况下是如何工作的，但是在 C 类中，我需要根据传入的对象的属性进行解析。

我想我要问的是，容器是否变成了依赖关系，因此，如何最好地将其获取到需要的地方（不确定我是否真的想通过一堆构造函数传递它 - 属性注入会是正确的方法吗？）

我相信这个来源是我能得到的最干净和简单的：

namespace InjectionTest
{
    using System;
    using Microsoft.Practices.Unity;

    public class ApplicationA
    {
        static void Main(string[] args)
        {
            using (IUnityContainer container = new UnityContainer())
            {
                // Normally I'd use this, but for clarity in the example, I'm doing it in code.
                //container.LoadConfiguration(); 
                container.RegisterType<IClassB, ClassB>();
                container.RegisterType<IClassC, ClassC>();
                container.RegisterType<IFooBuilder, FrobBuilder>("frob");
                container.RegisterType<IFooBuilder, WidgetBuilder>("widget");
                IClassB machine = container.Resolve<IClassB>();
                InitialObject bar = new InitialObject() { Name = "widget" };
                machine.doSomethingWithBar(bar);
                bar = new InitialObject() { Name = "frob" };
                machine.doSomethingWithBar(bar);
            }
        }
    }

    public class ClassB : IClassB
    {
        IClassC classC { get; private set; }

        public ClassB(IClassC classc)
        {
            this.classC = classc;
        }

        public void doSomethingWithBar(InitialObject bar)
        {
            var foo = this.classC.BuildMyFoo(bar);
            /*
             * Do something else with foo & bar
             * */
        }

    }

    public interface IClassB
    {
        void doSomethingWithBar(InitialObject bar);
    }

    public class ClassC : IClassC
    {
        public ResultObject BuildMyFoo(InitialObject bar)
        {
            IFooBuilder builder = null;
            //How best do I get my container here?
            //IFooBuilder builder = container.Resolve<IFooBuilder>(bar.Name);
            return builder.build(bar);
        }
    }

    public interface IClassC
    {
        ResultObject BuildMyFoo(InitialObject bar);
    }

    public class InitialObject
    {
        public string Name { get; set; }
    }

    public class ResultObject
    {
        public string SomeOtherData { get; set; }
    }

    public interface IFooBuilder
    {
        ResultObject build(InitialObject bar);
    }

    public class FrobBuilder : IFooBuilder
    {
        public ResultObject build(InitialObject bar)
        {
            throw new NotImplementedException();
        }
    }

    public class WidgetBuilder : IFooBuilder
    {
        public ResultObject build(InitialObject bar)
        {
            throw new NotImplementedException();
        }
    }
}

---

编辑：这就是我如何让它与属性注入一起工作：

我更改了 ClassC：

public class ClassC : IClassC
{
    [Dependency]
    public IUnityContainer Container { get; set; }

    public ResultObject BuildMyFoo(InitialObject bar)
    {
        IFooBuilder builder = null;
        //How best do I get my container here?
        builder = Container.Resolve<IFooBuilder>(bar.Name);
        return builder.build(bar);
    }
}

并更新了 ApplicationA 中的 Main 方法：

    public void Main()
    {
        using (IUnityContainer container = new UnityContainer())
        {
            // Normally I'd use this, but for clarity in the example, I'm doing it in code.
            //container.LoadConfiguration(); 
            container.RegisterType<IClassB, ClassB>();
            container.RegisterType<IClassC, ClassC>();
            container.RegisterType<IFooBuilder, FrobBuilder>("frob");
            container.RegisterType<IFooBuilder, WidgetBuilder>("widget");
            using (IUnityContainer child = container.CreateChildContainer())
            {
                container.RegisterInstance<IUnityContainer>(child);
                IClassB machine = container.Resolve<IClassB>();
                InitialObject bar = new InitialObject() { Name = "widget" };
                machine.doSomethingWithBar(bar);
                bar = new InitialObject() { Name = "frob" };
                machine.doSomethingWithBar(bar);
            }
        }
    }

Answer 1

您绝对不想传递容器。您应该查看在这种情况下适用的 Unity 工厂支持。像这样：

container.RegisterType<IFooBuilder, FrobBuilder>("Frob")
         .RegisterType<IFooBuilder, WidgetBuilder>("Widget")
         .RegisterType<Func<string, IFooBuilder>>(new InjectionFactory(c => new Func<string, IFooBuilder>(barName => c.Resolve<IFooBuilder>(barName))))

然后 ClassC 将有一个 Func 的构造函数参数：

public class ClassC : IClassC
{
  private readonly Func<string, IFooBuilder> _builderFactory;

  public ClassC(Func<string, IFooBuilder> builderFactory)
  {
    _builderFactory = builderFactory;
  }

  public ResultObject BuildMyFoo(InitialObject bar)
  {
    IFooBuilder builder = _builderFactory(bar.Name);
    return builder.build(bar);
  }
}