使用MVC3 IDependencyResolver解析Unity2.0中的命名注册

Question

所有人！

我在使用MVC3 IDependencyResolver解析Unity2.0中的命名注册时遇到了问题。

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>();
        }
    }
}

而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 );
}

我想要做的是，无论是在UnityDependencyResolver中还是以任何其他方式，如果命名实例不存在，则解析我的命名实例或默认实例。当前代码始终解析为默认实例(没有命名实例)。

有没有人知道怎么做？

谢谢。

Answer 1

据我所知，您尝试将IService注入到一些控制器中：

public class HomeController : Controller
{
  private IService _service;

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

然后您可以这样做(您应该显式地为每个控制器分配命名实例)：

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

您不应该将注册名称传递给mvc解析器，因为它是没有意义的(我们只有一种(默认命名的)控制器类型)：

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为什么你需要一些IService - default和named的实例？