使用 'Autofac.Core.Activators.Reflection.DefaultConstructorFinder' 找到的构造函数的 Autofac None

Question

None of the constructors found with 'Autofac.Core.Activators.Reflection.DefaultConstructorFinder' on type 'LMS.Services.Security.EncryptionService' can be invoked with the available services and parameters: Cannot resolve parameter 'LMS.Models.SecuritySettings securitySettings' of constructor 'Void .ctor(LMS.Models.SecuritySettings)'

这是代码文件

服务Class

public class EncryptionService : IEncryptionService
{
    private readonly SecuritySettings _securitySettings;
    public EncryptionService(SecuritySettings securitySettings)
    {
        this._securitySettings = securitySettings;
    }
}

引导程序

private static void SetAutofacContainer()
{
    var builder = new ContainerBuilder();
    builder.RegisterControllers(Assembly.GetExecutingAssembly());
    builder.RegisterType<UnitOfWork>().As<IUnitOfWork>().InstancePerRequest();
    builder.RegisterType<DatabaseFactory>().As<IDatabaseFactory>().InstancePerRequest();

    builder.RegisterAssemblyTypes(typeof(CourseRepository).Assembly)
           .Where(t => t.Name.EndsWith("Repository"))
           .AsImplementedInterfaces()
           .InstancePerRequest();

    builder.RegisterAssemblyTypes(typeof(CourseService).Assembly)
           .Where(t => t.Name.EndsWith("Service"))
           .AsImplementedInterfaces()
           .InstancePerRequest();

    builder.RegisterFilterProvider();
    var container = builder.Build();
    DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
}

它早些时候工作。但是当我引入 EncryptionService 实现时，我收到了上述错误。这是其他工作代码实现如下

public class CourseService : ICourseService
{
    #region Fields

    private readonly IRepository<Course> _courseRepository;
    private readonly IUnitOfWork _unitOfWork;

    #endregion

    #region ctor

    public CourseService(IRepository<Course> courseRepository, IUnitOfWork unitOfWork)
    {
        _courseRepository = courseRepository;
        _unitOfWork = unitOfWork;
    }
    #endregion
}

Answer 1

当 Autofac 尝试解析 EncryptionService 时，它会尝试解析 SecuritySettings 服务，但 Autofac 不是知道这样的注册。

要解决此错误，您应该注册一个 SecuritySettings 实现。

例如：

builder.RegisterType<SecuritySettings>()
       .As<SecuritySettings>();

Answer 2

您还可以通过添加 AnyConcreteTypeNotAlreadyRegisteredSource（请参阅 the docs for Sources）调整 Autofac 的行为以按您最初预期的方式工作[并与其他一些容器的默认值保持一致]：-

var builder = new ContainerBuilder();
builder.RegisterSource(new AnyConcreteTypeNotAlreadyRegisteredSource());

我已经将此方案与 delegate factories and implicit Relationship Types 一起使用，几乎从一套应用程序中删除了显式注册，但由于您似乎已经走上了显式（boilerplaty :P）注册的道路，我建议谷歌搜索 AnyConcreteTypeNotAlreadyRegisteredSource 以查看更广泛的方案是否更符合您的要求。

Answer 3

就我而言，我还没有注册上下文。我注册了上下文，它对我有用

builder.RegisterType<JComDbEntities>().AsSelf().As<DbContext>().InstancePerLifetimeScope();

使用 'Autofac.Core.Activators.Reflection.DefaultConstructorFinder' 找到的构造函数的 Autofac None

Autofac None of the constructors found with 'Autofac.Core.Activators.Reflection.DefaultConstructorFinder'

c#

dependency-injection

inversion-of-control

autofac

ioc-container