依赖注入 – Autofac.Core.DependencyResolutionException

发布时间：2020-12-14 04:55:03 所属栏目：百科来源：网络整理

导读：Autofac新手在这里想要更好地理解以下异常,任何帮助/指针将非常感谢！ Unhandled Exception: Autofac.Core.DependencyResolutionException: None of the constructors found with 'Public binding flags' on type 'Test.Authorization.LoginService' can be

Autofac新手在这里想要更好地理解以下异常,任何帮助/指针将非常感谢！

Unhandled Exception: 
    Autofac.Core.DependencyResolutionException: 
        None of the constructors found with 'Public binding flags' on type 'Test.Authorization.LoginService' can be invoked with the available services and parameters: 
         Cannot resolve parameter 'System.Func`1[System.IO.Stream] readStream' of constructor 'Void .ctor(System.Func`1[System.IO.Stream],System.Func`1[System.IO.Stream])'.
    at Autofac.Core.Activators.Reflection.ReflectionActivator.ActivateInstance(IComponentContext context,IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreActivatorsReflectionReflectionActivator.cs:line 117    
    at Autofac.Core.Resolving.InstanceLookup.Activate(IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreResolvingInstanceLookup.cs:line 79
    at Autofac.Core.Resolving.InstanceLookup.Execute() in autofacsrcSourceAutofacCoreResolvingInstanceLookup.cs:line 62
    at Autofac.Core.Resolving.ResolveOperation.GetOrCreateInstance(ISharingLifetimeScope currentOperationScope,IComponentRegistration registration,IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreResolvingResolveOperation.cs:line 124
    at Autofac.Core.Resolving.InstanceLookup.ResolveComponent(IComponentRegistration registration,IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreResolvingInstanceLookup.cs:line 115  
    at Autofac.Features.Collections.CollectionRegistrationSource.c__DisplayClass4.c__DisplayClass6.b__1(IComponentRegistration cr) in autofacsrcSourceAutofacFeaturesCollectionsCollectionRegistrationSource.cs:line 80    at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext()  
    at System.Linq.Buffer`1..ctor(IEnumerable`1 source)    
    at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
    at Autofac.Features.Collections.CollectionRegistrationSource.c__DisplayClass4.b__0(IComponentContext c,IEnumerable`1 p) in autofacsrcSourceAutofacFeaturesCollectionsCollectionRegistrationSource.cs:line 80    
    at Autofac.Core.Activators.Delegate.DelegateActivator.ActivateInstance(IComponentContext context,IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreActivatorsDelegateDelegateActivator.cs:line 65
    at Autofac.Core.Resolving.InstanceLookup.Activate(IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreResolvingInstanceLookup.cs:line 79   
    at Autofac.Core.Resolving.InstanceLookup.Execute() in autofacsrcSourceAutofacCoreResolvingInstanceLookup.cs:line 62   
    at Autofac.Core.Resolving.ResolveOperation.GetOrCreateInstance(ISharingLifetimeScope currentOperationScope,IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreResolvingResolveOperation.cs:line 124    
    at Autofac.Core.Resolving.InstanceLookup.ResolveComponent(IComponentRegistration registration,IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreResolvingInstanceLookup.cs:line 115  
    at Autofac.Core.Activators.Reflection.AutowiringParameter.c__DisplayClass2.b__0() in autofacsrcSourceAutofacCoreActivatorsReflectionAutowiringParameter.cs:line 51    
    at Autofac.Core.Activators.Reflection.ConstructorParameterBinding.Instantiate() in autofacsrcSourceAutofacCoreActivatorsReflectionConstructorParameterBinding.cs:line 113    
    at Autofac.Core.Activators.Reflection.ReflectionActivator.ActivateInstance(IComponentContext context,IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreActivatorsReflectionReflectionActivator.cs:line 119    
    at Autofac.Core.Resolving.InstanceLookup.Activate(IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreResolvingInstanceLookup.cs:line 79   
    at Autofac.Core.Resolving.InstanceLookup.b__0() in autofacsrcSourceAutofacCoreResolvingInstanceLookup.cs:line 64   
    at Autofac.Core.Lifetime.LifetimeScope.GetOrCreateAndShare(Guid id,Func`1 creator) in autofacsrcSourceAutofacCoreLifetimeLifetimeScope.cs:line 269    
    at Autofac.Core.Resolving.InstanceLookup.Execute() in autofacsrcSourceAutofacCoreResolvingInstanceLookup.cs:line 64   
    at Autofac.Core.Resolving.ResolveOperation.GetOrCreateInstance(ISharingLifetimeScope currentOperationScope,IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreResolvingResolveOperation.cs:line 124    
    at Autofac.Core.Resolving.ResolveOperation.ResolveComponent(IComponentRegistration registration,IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreResolvingResolveOperation.cs:line 69 
    at Autofac.Core.Resolving.ResolveOperation.Execute(IComponentRegistration registration,IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreResolvingResolveOperation.cs:line 96 
    at Autofac.Core.Lifetime.LifetimeScope.ResolveComponent(IComponentRegistration registration,IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreLifetimeLifetimeScope.cs:line 235    
    at Autofac.Core.Container.ResolveComponent(IComponentRegistration registration,IEnumerable`1 parameters) in autofacsrcSourceAutofacCoreContainer.cs:line 191    
    at Autofac.ResolutionExtensions.TryResolveService(IComponentContext context,Service service,IEnumerable`1 parameters,Object& instance) in autofacsrcSourceAutofacResolutionExtensions.cs:line 728    
    at Autofac.ResolutionExtensions.ResolveService(IComponentContext context,IEnumerable`1 parameters) in autofacsrcSourceAutofacResolutionExtensions.cs:line 346    
    at Autofac.ResolutionExtensions.Resolve(IComponentContext context,Type serviceType,IEnumerable`1 parameters) in autofacsrcSourceAutofacResolutionExtensions.cs:line 244    at Autofac.ResolutionExtensions.Resolve[TService](IComponentContext context,IEnumerable`1 parameters) in autofacsrcSourceAutofacResolutionExtensions.cs:line 197    
    at Autofac.ResolutionExtensions.Resolve[TService](IComponentContext context,Parameter[] parameters) in autofacsrcSourceAutofacResolutionExtensions.cs:line 213

public sealed class AuthorizationModule : Module
{
    protected override void Load(ContainerBuilder builder)
    {
        builder
        .Register(LoginService)
        .AsImplementedInterfaces()
        .SingleInstance();
    }

 static LoginService LoginService(IComponentContext c)
 {
     var file = c.Resolve<IFile>();
     var dataPath = <Some Path>;

     return new LoginService
     (readStream: () => file.Open(dataPath),writeStream: () => file.Create(dataPath));
 }
}


sealed class LoginService : TLoginService.Iface,IService
{
    readonly Func<Stream> _readStream;
    readonly Func<Stream> _writeStream;
    readonly XmlSerializer _serializer;

    public LoginService(
      Func<Stream> readStream,Func<Stream> writeStream
    )
    {
       Contract.Requires(readStream != null);
       Contract.Requires(writeStream != null);
       _readStream = readStream;
       _writeStream = writeStream;
       _serializer = new XmlSerializer(typeof (List<LoginRecord>));
 }
 ...
 ...

解决方法

您的LoginService类有一个类似于LoginService的构造函数(Func< System.IO.Stream> stream). Autofac无法创建Func< System.IO.Stream>论点.因此,请适当注册,以便Autofac可以创建LoginService.

例如：

builder.Register(c => new LoginService(d => File.Open("Foo));

浏览Wiki的Component Registration部分,找??出适合您的方法.

（编辑：李大同）

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