how to implement Open Generic Constructor Injection in Dot Net Core

Question

I have an interface for Audit Logging:

public interface IAuditDbContext<T1, T2>
{
   T1 AuditLog { get; set; }
   T2 ChangeTracker { get; }
}

now in main AppDbContext interface, I am inheriting this as:

public interface IAppDBContext<T1, T2> : IAuditDbContext<T1,T2>
{
    Task<int> SaveChangesAsync(CancellationToken cancellationToken);
}

and in main AppDbContext class, I am inheriting as:

public class AppDBContext : DbContext, IAppDBContext<DbSet<Audit>, ChangeTracker>
{
 ....
}

The problem is, at the time of Dependency Injection, I am trying to inject it like:

services.AddScoped(
    typeof(IAppDBContext<,>),
    typeof(IAuditDbContext<,>).MakeGenericType(typeof(AppDBContext)));

I have tried other ways as well, but not able to get the success - some error messages that I am getting are:

Error Messages:

1. Message=The number of generic arguments provided doesn't equal the arity of the generic type definition.
2. Cannot instantiate implementation type 'Common.Application.Interfaces. IAuditDbContext 2[T1,T2]' for service type 'Common.Application.Interfaces.IAppDBContext 2[T1,T2]'

Requesting help to implement it correctly.

Answer 1

typeof(IAuditDbContext<,>).MakeGenericType(typeof(AppDBContext))

You have two generic parameters in IAuditDbContext interface, so you need to provide two parameters for MakeGenericType method.

But , I'm not sure that it is what you need. You should map interfaces to some classes that might be initiated, not interfaces.

services.AddScoped(typeof(IAppDBContext<,>), typeof(AppDBContext)); //example

But Do you really need to register open generic type?