c# - 使用 MVC3 IDependencyResolver 从 Unity 2.0 解析命名注册

Question

各位!

我在使用 MVC3 IDependencyResolver 从 Unity 2.0 解析命名注册时遇到问题。

我将类型注册配置为

public class Implementations
{
    private IUnityContainer unityContainer;

    internal Implementations()
    {
        this.unityContainer = new UnityContainer();
    }

    public static IUnityContainer GetUnityContainer()
    {
        Implementations implementations = new Implementations();

        implementations.RegisterImplementations();

        return implementations.unityContainer;
    }

    private void RegisterImplementations()
    {
        this.unityContainer
            .RegisterType<IService, TestService>()
            .RegisterType<IService, TestService2>("ts2");
    }
}

IDependencyResolver 的代码是

public class UnityDependencyResolver : IDependencyResolver
{
    IUnityContainer container = null;
    string namedRegistration = null;

    public UnityDependencyResolver(IUnityContainer container, string name)
    {
        this.container = container;
        this.namedRegistration = name;
    }

    public object GetService(Type serviceType)
    {
        try
        {
            return this.container.Resolve(serviceType, this.namedRegistration);
        }
        catch
        {
            return null;
        }
    }

    public IEnumerable<object> GetServices(Type serviceType)
    {
        try
        {
            return this.container.ResolveAll(serviceType);
        }
        catch
        {
            return new List<object>();
        }
    }
}

Application_Start 中的方法调用是

protected void Application_Start()
{
    var dependency =
        new UnityDependencyResolver(Implementations.GetUnityContainer(), "ts2");
    DependencyResolver.SetResolver(dependency);

    AreaRegistration.RegisterAllAreas();

    RegisterGlobalFilters( GlobalFilters.Filters );
    RegisterRoutes( RouteTable.Routes );
}

无论是在 UnityDependencyResolver 还是任何其他方式中，我想做的是解析我的命名实例或默认实例(如果命名不存在)。当前代码始终解析为默认实例(无命名实例)。

有人知道怎么做吗？

谢谢。

Answer 1

据我了解，您尝试使用 IService 注入(inject)某些 Controller :

public class HomeController : Controller
{
  private IService _service;

  public HomeController(IService service)
  {
    _service = service;
  }
// ..
}

然后你可以这样做(你应该为每个 Controller 显式分配命名实例):

private void RegisterImplementations()
{
  _unityContainer
    .RegisterType<IService, Service1>()
    .RegisterType<IService, Service2>("ts2")
    .RegisterType<HomeController>(new InjectionConstructor(new ResolvedParameter<IService>("ts2")));
}

并且您不应该将注册名称传递给 mvc 解析器，因为它没有意义(我们只有一种(默认命名的) Controller 类型):

public class UnityDependencyResolver : IDependencyResolver
{
  private readonly IUnityContainer container;

  public UnityDependencyResolver(IUnityContainer container)
  {
    this.container = container;
  }

  #region IDependencyResolver Members

  public object GetService(Type serviceType)
  {
    try
    {
      return container.Resolve(serviceType);
    }
    catch
    {
      return null;
    }
  }
// ..
}

PS 为什么需要一些 IService 实例 - 默认和命名？