How is a Factory class registered in .NET 8?

Could someone please show me how I register the following Factory in .NET 8?:

public class DefaultViewFactory : IViewFactory
{
    private readonly IServiceProvider _serviceProvider;

    public DefaultViewFactory(IServiceProvider serviceProvider)
    {
        _serviceProvider = serviceProvider;
    }

    public TView CreateView<TView>()
    {
        var service = _serviceProvider.GetService<IViewBuilder<TView>>();

        return service != null ? service.Build() : Activator.CreateInstance<TView>();
    }

    public TView CreateView<TInput, TView>(TInput input)
    {
        var service = _serviceProvider.GetService<IViewBuilder<TInput, TView>>();

        if (service != null)
        {
            return service.Build(input);
        }

        return (TView)Activator.CreateInstance(typeof(TView), input)!;
    }
}

I’ve added the following code to the Program.cs file:

serviceCollection.AddTransient<IViewFactory, DefaultViewFactory>();

Previously using StructureMap, the following would be used:

configurationExpression.Scan(assemblyScanner =>
{
    assemblyScanner.TheCallingAssembly();
    assemblyScanner.ConnectImplementationsToTypesClosing(typeof(IViewBuilder<>));
    assemblyScanner.ConnectImplementationsToTypesClosing(typeof(IViewBuilder<,>));
})

Could someone please advise an alternative implementation?

I have added the IViewBuilder for reference:

public interface IViewBuilder<out TView>
{
    TView Build();
}

public interface IViewBuilder<in TInput, out TView>
{
    TView Build(TInput input);
}

>Solution :

.NET (Core) build-in DI does not support assembly scanning and matching closed generic types.

If you have a single open generic implementation then you can register it as open generic:

services.AddTransient(typeof(IViewBuilder<>), typeof(SomeGenericViewBuilder<>));
services.AddTransient(typeof(IViewBuilder<,>), typeof(SomeGenericViewBuilder<,>));

If you have different types implementing the interface then you can:

• Register them manually:

  services.AddTransient(typeof(IViewBuilder<SomeView>), typeof(SomeViewBuilder));
  // ...
  

• Write assembly scanning code yourself (using reflection APIs)

• Use some library like Scrutor (not tested):

  var collection = new ServiceCollection();
  
  collection.Scan(scan => scan
     // We start out with all types in the assembly
      .FromAssemblyOf<ViewBuildersAssemblyTypeLandmark>()
        // Generic interfaces are also supported too
        .AddClasses(classes => classes.AssignableTo(typeof(IViewBuilder<>)))
            .AsImplementedInterfaces()
        // And you scan generics with multiple type parameters 
        .AddClasses(classes => classes.AssignableTo(typeof(IViewBuilder<,>)))
            .AsImplementedInterfaces());
  

• Look into replacing default service container with one which supports needed functionality