没有范围与标签匹配的'AutofacWebRequest'是可见的范围

Question

新近AutoFac最近使用SimpleInjector，但由于我已升级到vNext/.NET5，AutoFac似乎更新与它一起使用，所以使用AutoFac代替。

我想要做的就是确保我的DbContext是在每个请求上创建的。我可以通过使用.InstancePerRequest()做到这一点，但是当我这样做（我已经添加到我的代码），我似乎获得错误信息

Autofac.Core.DependencyResolutionException有标签 匹配“没有范围AutofacWebRequest '在请求实例的范围内可见。这种通常表示为每HTTP请求由 SingleInstance（）成分请求是一个组件 注册（或类似的情况。）在卷筒纸 积分总是请求来自 DependencyResolver.Current或ILifetimeScopeProvider.RequestLifetime， 依赖性从来没有从容器本身。

我相信这是说没有东西被请求，因为每个HTTP请求，所以什么都不会？是对的吗？如果是这样，有点似乎有点愚蠢。我不关心，如果我的服务和验证，才能创建一次，但我需要对每个请求创建的DbContext，当多个请求连接到我的WebAPI的，我不断收到一个错误说

第二次手术开始这个上下文在之前的 异步操作完成之前。

但是，如果我一个接一个地执行这些调用，那么它们都可以正常工作。

我使用的是EntityFramework 6.1，而不是EF7，因为EF7还远没有完成。

我有我的AutoFac模块，像这样

public class SetupModule : Autofac.Module 
{ 
    protected override void Load(ContainerBuilder builder) 
    { 
     // IDataContext 
     builder.Register((c) => 
      { 
       var appEnv = c.Resolve<IApplicationEnvironment>(); 
       var configBuilder = new ConfigurationBuilder(appEnv.ApplicationBasePath) 
        .AddJsonFile("config.json"); 
       var configuration = configBuilder.Build(); 

       return new DataContext(configuration["Data:MyConnection:ConnectionString"]); 
      }) 
      .As<IDataContext>() 
      .InstancePerRequest(); 

     // Validators 
     builder.RegisterAssemblyTypes(System.Reflection.Assembly.GetAssembly(typeof(IValidator))) 
      .Where(t => typeof(IValidator).IsAssignableFrom(t)) 
      .AsImplementedInterfaces() 
      .InstancePerRequest(); 

     // Services 
     builder.RegisterType<ContentService>().As<IContentService>().InstancePerRequest(); 

    } 
} 

我的DataContext是像构造一个标准的DbContext类，只是采取的connectionString

public DataContext : IDataContext { 
    public DataContext(string connectionString) 
     : base(connectionString) 
     { 

     } 
} 

在我Startup.cs文件我注册这个使用这个

public IServiceProvider ConfigureServices(IServiceCollection services) 
{ 
    // Create the Autofac container builder. 
    var builder = new ContainerBuilder(); 
    builder.RegisterModule(new AutoFac.SetupModule()); 
    builder.Populate(services); 

    // Build the container. 
    var container = builder.Build(); 

    // Resolve and return the service provider. 
    return container.Resolve<IServiceProvider>(); 
} 

有人能告诉我到底什么是我想念G？这是否与我如何创建我的DataContext有关，因为需要这样做才能从config.json文件获取connectionString。

在此先感谢

注：如果我更改为.InstancePerDependency()我停止错误，但我不认为这是我想对所有对象

UPDATE 这里是堆栈跟踪

at Autofac.Core.Lifetime.MatchingScopeLifetime.FindScope(ISharingLifetimeScope mostNestedVisibleScope) 
at Autofac.Core.Resolving.InstanceLookup..ctor(IComponentRegistration registration, IResolveOperation context, ISharingLifetimeScope mostNestedVisibleScope, IEnumerable<Parameter> parameters) 
at Autofac.Core.Resolving.ResolveOperation.GetOrCreateInstance(ISharingLifetimeScope currentOperationScope, IComponentRegistration registration, IEnumerable<Parameter> parameters) 
at Autofac.Core.Resolving.ResolveOperation.ResolveComponent(IComponentRegistration registration, IEnumerable<Parameter> parameters) 
at Autofac.Core.Resolving.ResolveOperation.Execute(IComponentRegistration registration, IEnumerable<Parameter> parameters) 
at Autofac.Core.Lifetime.LifetimeScope.ResolveComponent(IComponentRegistration registration, IEnumerable<Parameter> parameters) 
at Autofac.ResolutionExtensions.TryResolveService(IComponentContext context, Service service, IEnumerable<Parameter> parameters, Object& instance) 
at Autofac.ResolutionExtensions.ResolveOptionalService(IComponentContext context, Service service, IEnumerable<Parameter> parameters) 
at Autofac.ResolutionExtensions.ResolveOptional(IComponentContext context, Type serviceType, IEnumerable<Parameter> parameters) 
at Autofac.ResolutionExtensions.ResolveOptional(IComponentContext context, Type serviceType) 
at Autofac.Framework.DependencyInjection.AutofacServiceProvider.GetService(Type serviceType) 
at Microsoft.Framework.DependencyInjection.ActivatorUtilities.GetService(IServiceProvider sp, Type type, Type requiredBy, Boolean isDefaultParameterRequired) 
.lambda_method(Closure , IServiceProvider , Object[]) 
at Microsoft.AspNet.Mvc.DefaultTypeActivatorCache.CreateInstance<TInstance>(IServiceProvider serviceProvider, Type implementationType) 
at Microsoft.AspNet.Mvc.DefaultControllerActivator.Create(ActionContext actionContext, Type controllerType) 
at Microsoft.AspNet.Mvc.DefaultControllerFactory.CreateController(ActionContext actionContext) 
at Microsoft.AspNet.Mvc.Core.ControllerActionInvoker.CreateInstance() 
at Microsoft.AspNet.Mvc.Core.FilterActionInvoker.<InvokeAllActionFiltersAsync>d__49.MoveNext() 
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.GetResult() 
at Microsoft.AspNet.Mvc.Core.FilterActionInvoker.<InvokeExceptionFilterAsync>d__48.MoveNext() 
--- exception rethrown --- 
at Microsoft.AspNet.Mvc.Core.FilterActionInvoker.<InvokeAsync>d__41.MoveNext() 
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.GetResult() 
at Microsoft.AspNet.Mvc.MvcRouteHandler.<InvokeActionAsync>d__7.MoveNext() 
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.GetResult() 
at Microsoft.AspNet.Mvc.MvcRouteHandler.<RouteAsync>d__6.MoveNext() 
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.GetResult() 
at Microsoft.AspNet.Mvc.Routing.InnerAttributeRoute.<RouteAsync>d__10.MoveNext() 
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.GetResult() 
at Microsoft.AspNet.Routing.RouteCollection.<RouteAsync>d__9.MoveNext() 
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.GetResult() 
at Microsoft.AspNet.Builder.RouterMiddleware.<Invoke>d__4.MoveNext() 
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.GetResult() 
at Microsoft.AspNet.Hosting.Internal.RequestServicesContainerMiddleware.<Invoke>d__3.MoveNext() 
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.GetResult() 
at Microsoft.AspNet.Hosting.Internal.HostingEngine.<>c__DisplayClass29_0.<<Start>b__0>d.MoveNext() 
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.GetResult() 
at Microsoft.AspNet.Loader.IIS.RuntimeHttpApplication.<ProcessRequestAsyncImpl>d__13.MoveNext() 
--- exception rethrown --- 
at Microsoft.AspNet.Loader.IIS.RuntimeHttpApplication.<ProcessRequestAsyncImpl>d__13.MoveNext() 
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
at System.Runtime.CompilerServices.TaskAwaiter.GetResult() 
at Microsoft.AspNet.Loader.IIS.HttpApplicationBase.<InvokeProcessRequestAsyncImpl>d__9.MoveNext() 

Answer 1

看来，一件事情或两件事情都在发生：

• Autofac未与ASP.NET正确集成，并且未启动标记为AutofacWebRequest的新生命周期范围。
• 您正在解决在生命周期中已注册为InstancePerRequest()的组件，该组件的祖先不包含标记为AutofacWebRequest的生命周期范围。

看看堆栈跟踪，看起来第一种情况比第二种情况更可能，因为构建控制器时发生异常。