c# - 遵循教程后的 AutoFac.Core.DependencyResolutionException

Question

Autofac 的新手，遵循了 Youtube 上的教程(收视率很高)但它抛出异常，不知道为什么。

异常(exception)情况:

DependencyResolutionException: An error occurred during the activation of a particular registration. See the inner exception for details. Registration: Activator = IDomainRepository (ReflectionActivator), Services = [Solution.Entities.IDomainRepository], Lifetime = Autofac.Core.Lifetime.CurrentScopeLifetime, Sharing = None, Ownership = OwnedByLifetimeScope

和

NoConstructorsFoundException: No accessible constructors were found for the type 'Solution.Entities.IDomainRepository'.

IDomainRepository

public interface IDomainRepository
{
    List<Domain> GetAll();

    string Insert(Domain obj);

    bool Update(Domain obj);

    bool Delete(string URL);
}

域资源库

public class DomainRepository : IDomainRepository
{
    public List<Domain> GetAll()
    {
        using (IDbConnection db = new SqlConnection(Helper.ConnectionString))
        {
            if (db.State == ConnectionState.Closed)
            {
                db.Open();
            }
            return db.Query<Domain>("SELECT * FROM Domains", commandType: CommandType.Text).ToList();

        }
    }

    public string Insert(Domain obj)
    {
        using (IDbConnection db = new SqlConnection(Helper.ConnectionString))
        {
            if (db.State == ConnectionState.Closed)
            {
                db.Open();
            }
            db.Query<Domain>("INSERT INTO Domains (Domain) VALUES ("+obj.URL+")", commandType: CommandType.Text);
            return obj.URL;

        }
    }

    public bool Update(Domain obj)
    {
        using (IDbConnection db = new SqlConnection(Helper.ConnectionString))
        {
            if (db.State == ConnectionState.Closed)
            {
                db.Open();
            }
            int result = db.Execute("UPDATE Domains SET Domain="+obj.URL+" WHERE Domain="+obj.URL+")", commandType: CommandType.Text);
            return result != 0;

        }
    }

    public bool Delete(string URL)
    {
        using (IDbConnection db = new SqlConnection(Helper.ConnectionString))
        {
            if (db.State == ConnectionState.Closed)
            {
                db.Open();
            }
            int result = db.Execute("delete from Domains where Domain = @Url", new { Url = URL }, commandType: CommandType.Text);
            return result != 0;
        }
    }
}

域处理器

static Autofac.IContainer _container;

    static DomainHandler()
    {
        ContainerBuilder builder = new ContainerBuilder();
        builder.RegisterType<IDomainRepository>().As<IDomainRepository>();
        _container = builder.Build();
    }

    public static bool Delete(string Url)
    {
        return _container.Resolve<IDomainRepository>().Delete(Url);
    }

    public static List<Domain> GetAll()
    {
        return _container.Resolve<IDomainRepository>().GetAll();
    }

    public static Domain Save(Domain obj, EntityState state)
    {
        if (state == EntityState.Added)
            obj.URL = _container.Resolve<IDomainRepository>().Insert(obj);
        else
            _container.Resolve<IDomainRepository>().Update(obj);

        return obj;
    }

任何人都知道可能导致此错误的原因是什么？阅读有关忘记在界面上设置公共(public)访问权限的信息，但这不是这里的问题..:/

Answer 1

Anyone know what might be causing this error?

builder.RegisterType<IDomainRepository>().As<IDomainRepository>();
                     ^^

应该是

builder.RegisterType<DomainRepository>().As<IDomainRepository>();
                     ^

因为您需要 Concrete 类型的 RegisterType，而不是接口(interface)。

Autofac Registration Concepts

摘录:

Any component type you register via RegisterType must be a concrete type.