无法解决 IMemoryCache 依赖项

Question

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

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1. 在程序.cs中
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Host.CreateDefaultBuilder(args)\n    .ConfigureAppConfiguration(...)\n    ...etc\n    .UseServiceProviderFactory(new AutofacServiceProviderFactory())\n    .ConfigureServices((hostContext, services) =>\n    {\n        // Register configuration\n        services.AddMemoryCache();\n        // some another services\n    }\n    .ConfigureContainer<ContainerBuilder>(ConfigureContainer)\n    .UseConsoleLifetime();\n

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2. ConfigureContainer 是一种使用 autofac 注册某些类型的方法。
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3. 在我的服务中，我添加内存缓存依赖项，如下所示：
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    public class MyService: IMyService\n    {\n        private readonly IMemoryCache _memoryCache;\n        \n        public MyService(IMemoryCache memoryCache)\n        {\n            _memoryCache = memoryCache;\n        }\n    }\n

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但是当应用程序启动时我得到这个异常：

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Autofac.Core.DependencyResolutionException: An exception was thrown while activating \xce\xbb:Microsoft.Extensions.Hosting.IHostedService[] -> MyNamespace.WorkerService -> MyNamespace.MyAnotherService -> MyNamespace.SomeAnotherService -> MyNamespace.MyService -> Microsoft.Extensions.Caching.Memory.MemoryCache.\n ---> 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\'.\n ---> 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.\n   at Microsoft.Extensions.Caching.Memory.MemoryCache..ctor(IOptions`1 optionsAccessor)\n   at lambda_method(Closure , Object[] )\n   at Autofac.Core.Activators.Reflection.ConstructorParameterBinding.Instantiate()\n   --- End of inner exception stack trace ---\n   at Autofac.Core.Activators.Reflection.ConstructorParameterBinding.Instantiate()\n   at Autofac.Core.Activators.Reflection.ReflectionActivator.ActivateInstance(IComponentContext context, IEnumerable`1 parameters)\n   at Autofac.Core.Resolving.InstanceLookup.CreateInstance(IEnumerable`1 parameters)\n   --- End of inner exception stack trace ---\n   at Autofac.Core.Resolving.InstanceLookup.CreateInstance(IEnumerable`1 parameters)\n   at Autofac.Core.Resolving.InstanceLookup.Execute()\n   at Autofac.Core.Resolving.ResolveOperation.GetOrCreateInstance(ISharingLifetimeScope currentOperationScope, ResolveRequest request)\n   at Autofac.Core.Resolving.ResolveOperation.ResolveComponent(ResolveRequest request)\n   at Autofac.Core.Resolving.ResolveOperation.Execute(ResolveRequest request)\n   at Autofac.Core.Lifetime.LifetimeScope.ResolveComponent(ResolveRequest request)\n   at Autofac.ResolutionExtensions.TryResolveService(IComponentContext context, Service service, IEnumerable`1 parameters, Object& instance)\n   at Autofac.ResolutionExtensions.ResolveOptionalService(IComponentContext context, Service service, IEnumerable`1 parameters)\n   at Autofac.ResolutionExtensions.ResolveOptional(IComponentContext context, Type serviceType, IEnumerable`1 parameters)\n   at Autofac.ResolutionExtensions.ResolveOptional(IComponentContext context, Type serviceType)\n   at Autofac.Extensions.DependencyInjection.AutofacServiceProvider.GetService(Type serviceType)\n   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetService[T](IServiceProvider provider)\n   at Microsoft.Extensions.Hosting.Internal.Host.StartAsync(CancellationToken cancellationToken)\n   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token)\n   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token)\n   at MyNamespace.Program.Main(String[] args)\n

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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()如下内容（从.AddMemoryCache()正文复制粘贴）：

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

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但在这种情况下我得到另一个例外：

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

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有什么建议么？

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Answer 1

我发现了我的错误。多亏了 Sergey，我检查了我的 Program.cs，发现我.AddMemoryCache()曾经在ConfigureContainer 中注册 IMemoryCache 时使用过扩展。只需要使用扩展方法，无需手动注册IMemoryCache。