As the title says we’re in the process of migrating a system from .NET Framework to .NET Core. The original system used Ninject for DI migrating away from this has given us some trouble. There’s quite a bit of generated code in this project which uses generics.

The error that has us stuck is a runtime error:

Some services are not able to be constructed (Error while validating the service descriptor ‘ServiceType: ProjectNamespace.Core.Services.IAddressService Lifetime: Scoped ImplementationType: ProjectNamespace.Core.Services.AddressService’: Unable to resolve service for type ‘ProjectNamespace.Core.AddressMapper’ while attempting to activate ‘ProjectNamespace.Core.Repositories.AddressRepository’.) (Error while validating the service descriptor ‘ServiceType: ProjectNamespace.Core.Repositories.IAddressRepository Lifetime: Scoped ImplementationType: ProjectNamespace.Core.Repositories.AddressRepository’: Unable to resolve service for type ‘ProjectNamespace.Core.AddressMapper’ while attempting to activate ‘ProjectNamespace.Core.Repositories.AddressRepository’.)

Code:

// Startup.cs
services.AddGeneratedComponents();

// GeneratedRegistrations.cs
public static IServiceCollection AddGeneratedComponents(this IServiceCollection services)
{
    AddMySqlComponents(services);
    return services;
}

public static IServiceCollection AddMySqlComponents(this IServiceCollection services)
{
    GenericsHelper.Initialize(services);
    services.AddScoped(typeof(IGenericRepository<,,>), typeof(GenericRepository<,,>));
    return services;
}

// Generics.cs
public static IServiceCollection Initialize(this IServiceCollection services)
{
    services.AddScoped<IAddressMapper, AddressMapper>();
    services.AddScoped<IAddressService, AddressService>();
    services.AddScoped<IAddressRepository, AddressRepository>();

    return services;
}

public partial interface IAddressRepository : IGenericRepository<Address, AddressSearchCriteria, AddressMapper>
{
}

public partial class AddressRepository : GenericRepository<Address, AddressSearchCriteria, AddressMapper>, IAddressRepository
{
        public AddressRepository(AddressMapper mapper)
            : base(mapper)
        {
        }
}

Any help would be greatly appreciated, been wrestling with this for a few days now.

Not sure exactly where to start with this error. Happens a runtime and the source isn’t clear to me. It’s all happening under the hood so to speak.