.net core Can'；无法解析IMemoryCache依赖项

我有一个net.core 3.1托管服务应用程序。在此应用程序中，除了标准容器外，autofac还用作DI容器。我尝试添加并使用IMemoryCache，如下所示：

在Program.cs中

但我在应用程序启动时遇到了以下异常：

Autofac.Core.DependencyResolutionException: An exception was thrown while activating λ:Microsoft.Extensions.Hosting.IHostedService[] -> MyNamespace.WorkerService -> MyNamespace.MyAnotherService -> MyNamespace.SomeAnotherService -> MyNamespace.MyService -> Microsoft.Extensions.Caching.Memory.MemoryCache.
 ---> Autofac.Core.DependencyResolutionException: An exception was thrown while invoking the constructor 'Void .ctor(Microsoft.Extensions.Options.IOptions`1[Microsoft.Extensions.Caching.Memory.MemoryCacheOptions])' on type 'MemoryCache'.
 ---> System.TypeLoadException: Method 'get_Size' in type 'Microsoft.Extensions.Caching.Memory.CacheEntry' from assembly 'Microsoft.Extensions.Caching.Memory, Version=1.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' does not have an implementation.
   at Microsoft.Extensions.Caching.Memory.MemoryCache..ctor(IOptions`1 optionsAccessor)
   at lambda_method(Closure , Object[] )
   at Autofac.Core.Activators.Reflection.ConstructorParameterBinding.Instantiate()
   --- End of inner exception stack trace ---
   at Autofac.Core.Activators.Reflection.ConstructorParameterBinding.Instantiate()
   at Autofac.Core.Activators.Reflection.ReflectionActivator.ActivateInstance(IComponentContext context, IEnumerable`1 parameters)
   at Autofac.Core.Resolving.InstanceLookup.CreateInstance(IEnumerable`1 parameters)
   --- End of inner exception stack trace ---
   at Autofac.Core.Resolving.InstanceLookup.CreateInstance(IEnumerable`1 parameters)
   at Autofac.Core.Resolving.InstanceLookup.Execute()
   at Autofac.Core.Resolving.ResolveOperation.GetOrCreateInstance(ISharingLifetimeScope currentOperationScope, ResolveRequest request)
   at Autofac.Core.Resolving.ResolveOperation.ResolveComponent(ResolveRequest request)
   at Autofac.Core.Resolving.ResolveOperation.Execute(ResolveRequest request)
   at Autofac.Core.Lifetime.LifetimeScope.ResolveComponent(ResolveRequest request)
   at Autofac.ResolutionExtensions.TryResolveService(IComponentContext context, Service service, IEnumerable`1 parameters, Object& instance)
   at Autofac.ResolutionExtensions.ResolveOptionalService(IComponentContext context, Service service, IEnumerable`1 parameters)
   at Autofac.ResolutionExtensions.ResolveOptional(IComponentContext context, Type serviceType, IEnumerable`1 parameters)
   at Autofac.ResolutionExtensions.ResolveOptional(IComponentContext context, Type serviceType)
   at Autofac.Extensions.DependencyInjection.AutofacServiceProvider.GetService(Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetService[T](IServiceProvider provider)
   at Microsoft.Extensions.Hosting.Internal.Host.StartAsync(CancellationToken cancellationToken)
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token)
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token)
   at MyNamespace.Program.Main(String[] args)

我尝试在ConfigureContainer中使用autofac手动注册缓存服务所需的所有内容，而不是使用

.AddMemoryCache（）

，如下所示（从

.AddMemoryCache（）

正文复制粘贴）：

builder.RegisterType（typeof（optionmanager））.As（typeof（IOptions））.SingleInstance（）；
builder.RegisterType（typeof（optionmanager））.As（typeof（IOptionsSnapshot））；
RegisterType（typeof（OptionsMonitor））.As（typeof（IOptionsMonitor））.SingleInstance（）；
RegisterType（typeof（OptionsMonitor））.As（typeof（IOptionsFactory））.SingleInstance（）；
RegisterType（typeof（OptionsFactory））.As（typeof（IOptionsMonitorCache））.SingleInstance（）；
builder.RegisterType（）.As（）.SingleInstance（）；

但在这种情况下，我得到了另一个例外：

System.ArgumentException: The type 'Microsoft.Extensions.Options.OptionsManager`1[TOptions]' is not assignable to service 'Microsoft.Extensions.Options.IOptions`1'.
   at Autofac.Builder.RegistrationBuilder.CreateRegistration(Guid id, RegistrationData data, IInstanceActivator activator, Service[] services, IComponentRegistration target, Boolean isAdapterForIndividualComponent)
   at Autofac.Builder.RegistrationBuilder.CreateRegistration[TLimit,TActivatorData,TSingleRegistrationStyle](IRegistrationBuilder`3 builder)
   at Autofac.Builder.RegistrationBuilder.RegisterSingleComponent[TLimit,TActivatorData,TSingleRegistrationStyle](IComponentRegistryBuilder cr, IRegistrationBuilder`3 builder)
   at Autofac.RegistrationExtensions.<>c__DisplayClass3_0.<RegisterType>b__0(IComponentRegistryBuilder cr)
   at Autofac.ContainerBuilder.Build(IComponentRegistryBuilder componentRegistry, Boolean excludeDefaultModules)
   at Autofac.ContainerBuilder.Build(ContainerBuildOptions options)
   at Autofac.Extensions.DependencyInjection.AutofacServiceProviderFactory.CreateServiceProvider(ContainerBuilder containerBuilder)
   at Microsoft.Extensions.Hosting.Internal.ServiceFactoryAdapter`1.CreateServiceProvider(Object containerBuilder)
   at Microsoft.Extensions.Hosting.HostBuilder.CreateServiceProvider()
   at Microsoft.Extensions.Hosting.HostBuilder.Build()

System.ArgumentException:类型“Microsoft.Extensions.Options.OptionsManager`1[TopOptions]”不能分配给服务“Microsoft.Extensions.Options.IOOptions`1”。
在Autofac.Builder.RegistrationBuilder.CreateRegistration（Guid id、RegistrationData数据、IInstanceActivator激活器、服务[]服务、IComponentRegistration目标、布尔值IsAdapter for IndividualComponent）
在Autofac.Builder.RegistrationBuilder.CreateRegistration[TLimit，TActivatorData，TSingleRegistrationStyle]（IRegistrationBuilder`3 Builder）
在Autofac.Builder.RegistrationBuilder.RegisterSingleComponent[TLimit，TActivatorData，TSingleRegistrationStyle]（iComponentRegistrationBuilder cr，IRegistrationBuilder`3 Builder）
在Autofac.RegistrationExtensions.c__DisplayClass3_0.b__0（IComponentRegistryBuilder cr）上
在Autofac.ContainerBuilder.Build（IComponentRegistryBuilder componentRegistry，布尔排除默认模块）上
在Autofac.ContainerBuilder.Build上（ContainerBuildOptions）
位于Autofac.Extensions.DependencyInjection.AutofacServiceProviderFactory.CreateServiceProvider（ContainerBuilder ContainerBuilder）
位于Microsoft.Extensions.Hosting.Internal.ServiceFactoryAdapter`1.CreateServiceProvider（Object containerBuilder）
在Microsoft.Extensions.Hosting.HostBuilder.CreateServiceProvider（）上
在Microsoft.Extensions.Hosting.HostBuilder.Build（）上

---

有什么建议吗？

我发现了我的错误。感谢Sergey，我检查了Program.cs，发现我在ConfigureContainer中使用了

.AddMemoryCache（）

扩展名和register IMemoryCache。只需要使用扩展方法，不需要手动注册IMemoryCache。

您能提供

Program.cs

的完整代码吗？我无法复制，但在第二种情况下，当您手动添加依赖项时，我认为您可以只添加最后一个字符串。

Autofac.Core.DependencyResolutionException: An exception was thrown while activating λ:Microsoft.Extensions.Hosting.IHostedService[] -> MyNamespace.WorkerService -> MyNamespace.MyAnotherService -> MyNamespace.SomeAnotherService -> MyNamespace.MyService -> Microsoft.Extensions.Caching.Memory.MemoryCache.
 ---> Autofac.Core.DependencyResolutionException: An exception was thrown while invoking the constructor 'Void .ctor(Microsoft.Extensions.Options.IOptions`1[Microsoft.Extensions.Caching.Memory.MemoryCacheOptions])' on type 'MemoryCache'.
 ---> System.TypeLoadException: Method 'get_Size' in type 'Microsoft.Extensions.Caching.Memory.CacheEntry' from assembly 'Microsoft.Extensions.Caching.Memory, Version=1.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' does not have an implementation.
   at Microsoft.Extensions.Caching.Memory.MemoryCache..ctor(IOptions`1 optionsAccessor)
   at lambda_method(Closure , Object[] )
   at Autofac.Core.Activators.Reflection.ConstructorParameterBinding.Instantiate()
   --- End of inner exception stack trace ---
   at Autofac.Core.Activators.Reflection.ConstructorParameterBinding.Instantiate()
   at Autofac.Core.Activators.Reflection.ReflectionActivator.ActivateInstance(IComponentContext context, IEnumerable`1 parameters)
   at Autofac.Core.Resolving.InstanceLookup.CreateInstance(IEnumerable`1 parameters)
   --- End of inner exception stack trace ---
   at Autofac.Core.Resolving.InstanceLookup.CreateInstance(IEnumerable`1 parameters)
   at Autofac.Core.Resolving.InstanceLookup.Execute()
   at Autofac.Core.Resolving.ResolveOperation.GetOrCreateInstance(ISharingLifetimeScope currentOperationScope, ResolveRequest request)
   at Autofac.Core.Resolving.ResolveOperation.ResolveComponent(ResolveRequest request)
   at Autofac.Core.Resolving.ResolveOperation.Execute(ResolveRequest request)
   at Autofac.Core.Lifetime.LifetimeScope.ResolveComponent(ResolveRequest request)
   at Autofac.ResolutionExtensions.TryResolveService(IComponentContext context, Service service, IEnumerable`1 parameters, Object& instance)
   at Autofac.ResolutionExtensions.ResolveOptionalService(IComponentContext context, Service service, IEnumerable`1 parameters)
   at Autofac.ResolutionExtensions.ResolveOptional(IComponentContext context, Type serviceType, IEnumerable`1 parameters)
   at Autofac.ResolutionExtensions.ResolveOptional(IComponentContext context, Type serviceType)
   at Autofac.Extensions.DependencyInjection.AutofacServiceProvider.GetService(Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetService[T](IServiceProvider provider)
   at Microsoft.Extensions.Hosting.Internal.Host.StartAsync(CancellationToken cancellationToken)
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token)
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token)
   at MyNamespace.Program.Main(String[] args)

builder.RegisterType(typeof(OptionsManager<>)).As(typeof(IOptions<>)).SingleInstance();
builder.RegisterType(typeof(OptionsManager<>)).As(typeof(IOptionsSnapshot<>));
builder.RegisterType(typeof(OptionsMonitor<>)).As(typeof(IOptionsMonitor<>)).SingleInstance();
builder.RegisterType(typeof(OptionsMonitor<>)).As(typeof(IOptionsFactory<>)).SingleInstance();
builder.RegisterType(typeof(OptionsFactory<>)).As(typeof(IOptionsMonitorCache<>)).SingleInstance();
builder.RegisterType<MemoryCache>().As<IMemoryCache>().SingleInstance();

System.ArgumentException: The type 'Microsoft.Extensions.Options.OptionsManager`1[TOptions]' is not assignable to service 'Microsoft.Extensions.Options.IOptions`1'.
   at Autofac.Builder.RegistrationBuilder.CreateRegistration(Guid id, RegistrationData data, IInstanceActivator activator, Service[] services, IComponentRegistration target, Boolean isAdapterForIndividualComponent)
   at Autofac.Builder.RegistrationBuilder.CreateRegistration[TLimit,TActivatorData,TSingleRegistrationStyle](IRegistrationBuilder`3 builder)
   at Autofac.Builder.RegistrationBuilder.RegisterSingleComponent[TLimit,TActivatorData,TSingleRegistrationStyle](IComponentRegistryBuilder cr, IRegistrationBuilder`3 builder)
   at Autofac.RegistrationExtensions.<>c__DisplayClass3_0.<RegisterType>b__0(IComponentRegistryBuilder cr)
   at Autofac.ContainerBuilder.Build(IComponentRegistryBuilder componentRegistry, Boolean excludeDefaultModules)
   at Autofac.ContainerBuilder.Build(ContainerBuildOptions options)
   at Autofac.Extensions.DependencyInjection.AutofacServiceProviderFactory.CreateServiceProvider(ContainerBuilder containerBuilder)
   at Microsoft.Extensions.Hosting.Internal.ServiceFactoryAdapter`1.CreateServiceProvider(Object containerBuilder)
   at Microsoft.Extensions.Hosting.HostBuilder.CreateServiceProvider()
   at Microsoft.Extensions.Hosting.HostBuilder.Build()