使用 RegistrationBuilder 的 MEF 导出不起作用

Question

我正在尝试使用 [Export] 属性和注册生成器填充 MEF 目录。但是使用属性导出的服务可以解析，使用RegistrationBuilder注册的服务无法解析。看看下面我的代码：

static class Program
{
  [STAThread]
  static void Main()
  {
    // export service 2 using registration builder
    var builder = new RegistrationBuilder();
    builder.ForType<IService2>().Export<Service2>();

    var catalog = new AssemblyCatalog(Assembly.GetExecutingAssembly(), builder);
    var container = new CompositionContainer(catalog, CompositionOptions.DisableSilentRejection);
    container.SatisfyImportsOnce(builder);

    // service exported using attribute can be resolved
    var service1 = container.GetExport<IService1>();

    // throws 
    var service2 = container.GetExport<IService2>();
  }
}

// create two dummy services

public interface IService1 { }

public interface IService2 { }

// export service 1 with attribute
[Export(typeof(IService1))]
public class Service1 : IService1 { }

public class Service2 : IService2 { }

我做错了什么？有人可以帮我吗？谢谢！

Answer 1

尝试

builder.ForType<Service2>().Export<IService2>();

没有

builder.ForType<IService2>().Export<Service2>();

使用 RegistrationBuilder 的 MEF 导出不起作用

MEF Exporting using RegistrationBuilder does not work

c#

mef