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using System;
using Autofac;
namespace PropertyInjectionAutofacPoC
    public interface IInterfaceA { }
    public interface IInterfaceB
        IInterfaceA ClassA { get; set; }
    public class ClassA : IInterfaceA { }
    public class ClassB : IInterfaceB
        public IInterfaceA ClassA { get; set; } // this is injected properly //
    public class Z { }
    public interface IInterfaceC<T> { }
    public interface IInterfaceD<T>
        IInterfaceA ClassA { get; set; }
        IInterfaceC<T> ClassC { get; set; }
    public interface IInterfaceCZ : IInterfaceC<Z> { }
    public abstract class ClassD<T> : IInterfaceD<T>
        public IInterfaceA ClassA { get; set; } // this is not injected, it's always null //
        public IInterfaceC<T> ClassC { get; set; } // this is not injected, it's always null //
    public abstract class ClassC<T> : IInterfaceC<T> { }
    public sealed class ClassCZ : ClassC<Z>, IInterfaceCZ { }
    public interface IRepositoryZ : IInterfaceD<Z> { }
    public sealed class RepositoryZ : ClassD<Z>, IRepositoryZ { }
    internal class Program
        private static IContainer _container;
        private static void Main()
                RegisterServices();
                // it works //
                 var a = _container.Resolve<IInterfaceB>();
                 // it doesn't work //
                 var b = _container.Resolve<IRepositoryZ>(); // ClassC property is null
            catch (Exception e)
                Console.WriteLine(e);
            finally
                DisposeServices();
        private static void RegisterServices()
            var builder = new ContainerBuilder();
            builder.RegisterType<ClassA>().As<IInterfaceA>();
            builder.RegisterType<ClassB>().As<IInterfaceB>().PropertiesAutowired(); // works like a charm //
            builder.RegisterGeneric(typeof(ClassC<>)).As(typeof(IInterfaceC<>)).PropertiesAutowired();
            builder.RegisterGeneric(typeof(ClassD<>)).As(typeof(IInterfaceD<>)).PropertiesAutowired(); // it doesn't work //
            builder.RegisterType<ClassCZ>().As<IInterfaceCZ>();
            builder.RegisterType<RepositoryZ>().As<IRepositoryZ>();
            _container = builder.Build();
        private static void DisposeServices()
            if (_container != null &&
                _container is IDisposable disposable)
                disposable.Dispose();
}

private static void RegisterServices()
    var builder = new ContainerBuilder();
    builder.RegisterType<ClassA>().As<IInterfaceA>();
    builder.RegisterType<ClassB>().As<IInterfaceB>().PropertiesAutowired();
    // These registrations aren't really valid. You would never be able to
    // resolve IInterfaceC<> or IInterfaceD<>, because they are abstract classes, so cannot be constructed.
    // You'll always get a NoConstructorsFoundException.
    builder.RegisterGeneric(typeof(ClassC<>)).As(typeof(IInterfaceC<>)).PropertiesAutowired();
    builder.RegisterGeneric(typeof(ClassD<>)).As(typeof(IInterfaceD<>)).PropertiesAutowired();
    builder.RegisterType<ClassCZ>().As<IInterfaceCZ>();
    // When I resolve IRepositoryZ, this is the registration that gets provided. So this is where you need PropertiesAutowired.
    // Just because RepositoryZ derives from ClassD<Z> does not mean it inherits any of its component registration information,
    // which I think is what you may have been expecting.

问 使用generics<T>时不注入属性(PropertiesAutowired) EN

回答 1

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