C# 使用Autofac注入接口的特定实例

我有一个控制器，它接收一个接口的特定实例

界面如下所示：

public interface IMyInterface
{
   ... implementation goes here
}

public class MyClassA : IMyInterface
{
   ... implementation goes here
}

public class MyClassB : IMyInterface
{
   ... implementation goes here
}

public NewsController(INewsService newsService, IMapper newsMapper)
{
   Check.Argument.IsNotNull(newsService, "newsService");
   Check.Argument.IsNotNull(newsMapper, "newsMapper");

   this.newsService = newsService;
   this.newsMapper = newsMapper;
}

public class NewsMapper : IMapper
{
   static NewsMapper()
   {
      Mapper.CreateMap<News, NewsEditViewData>();
      Mapper.CreateMap<NewsEditViewData, News>();
   }

   public object Map(object source, Type sourceType, Type destinationType)
   {
      return Mapper.Map(source, sourceType, destinationType);
   }
}

然后我有一些实现这个接口的类，如下所示：

public interface IMyInterface
{
   ... implementation goes here
}

public class MyClassA : IMyInterface
{
   ... implementation goes here
}

public class MyClassB : IMyInterface
{
   ... implementation goes here
}

public NewsController(INewsService newsService, IMapper newsMapper)
{
   Check.Argument.IsNotNull(newsService, "newsService");
   Check.Argument.IsNotNull(newsMapper, "newsMapper");

   this.newsService = newsService;
   this.newsMapper = newsMapper;
}

public class NewsMapper : IMapper
{
   static NewsMapper()
   {
      Mapper.CreateMap<News, NewsEditViewData>();
      Mapper.CreateMap<NewsEditViewData, News>();
   }

   public object Map(object source, Type sourceType, Type destinationType)
   {
      return Mapper.Map(source, sourceType, destinationType);
   }
}

在我的ControllerA中，我有以下构造函数：

private ICustomerService customerService;
private IMyInterface myInterface;

puvlic ControllerA(ICustomerService customerService, IMyInterface myInterface)
{
   this.customerService = customerService;
   this.myInterface = myInterface;
}

在my global.ascx中：

protected void Application_Start()
{
   // Autofac
   var builder = new ContainerBuilder();
   builder.RegisterControllers(Assembly.GetExecutingAssembly());
   builder.RegisterType<NewsService>().As<INewsService>();

   IContainer container = builder.Build();
   DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
}

IMapper接口：

public interface IMapper
{
   object Map(object source, Type sourceType, Type destinationType);
}

我用的是AutoMapper。因此，我的新闻映射器将如下所示：

public interface IMyInterface
{
   ... implementation goes here
}

public class MyClassA : IMyInterface
{
   ... implementation goes here
}

public class MyClassB : IMyInterface
{
   ... implementation goes here
}

public NewsController(INewsService newsService, IMapper newsMapper)
{
   Check.Argument.IsNotNull(newsService, "newsService");
   Check.Argument.IsNotNull(newsMapper, "newsMapper");

   this.newsService = newsService;
   this.newsMapper = newsMapper;
}

public class NewsMapper : IMapper
{
   static NewsMapper()
   {
      Mapper.CreateMap<News, NewsEditViewData>();
      Mapper.CreateMap<NewsEditViewData, News>();
   }

   public object Map(object source, Type sourceType, Type destinationType)
   {
      return Mapper.Map(source, sourceType, destinationType);
   }
}

公共类新闻映射器：IMapper
{
静态新闻映射器（）
{
CreateMap（）；
CreateMap（）；
}
公共对象映射（对象源，类型sourceType，类型destinationType）
{
返回Mapper.Map（source、sourceType、destinationType）；
}
}

那么你建议我现在怎么做呢？

IIRC:

builder.RegisterType<MyClassB>().As<IMyInterface>()

---

它怎么知道这是给Controllerb的？ControllerA和ControllerB看起来是一样的，但它们只是在IMyInterface上得到了不同的实现。@jgauffin，我不同意。OP并没有说他的控制器不能处理其他类型的实例，他说他想注入不同类型的实例。让我们想象一下，他有一些提取数据的服务，他有一个包装这个数据服务并提供缓存功能的服务。我相信他们在这种情况下应该有相同的界面，注入正确的服务是DI的问题。@jgauffin+@Snowbear:请查看我的最新帖子，并请告诉我现在该怎么做？谢谢。@jgauffin:我要创建一个INewsMapper。谢谢你的建议。然后我需要为每个mapper？@jgauffin，+1为泛型解决方案创建一个接口，这与我使用的相同。但总的来说，我仍然相信，在某些情况下，您可能会为同一接口使用多个实现，并且希望在不创建标记接口的情况下注入它们。