微软默认的容器，不支持命名选项，同一接口，多个实现。 就不支持了。

配置core 支持Autofac 容器

using Autofac;
using Autofac.Extensions.DependencyInjection;

namespace WebApplication13
{
    public interface IMyService
    {
        string GetData();
    }

    public class MyService : IMyService
    {
        public string GetData()
        {
            return "Data from MyService---MyService";
        }
    }
    public class MyService2 : IMyService
    {
        public string GetData()
        {
            return "2222 from MyService---MyService2";
        }
    }
    public class MyApplicationModule : Module
    {
        protected override void Load(ContainerBuilder builder)
        {
            builder.RegisterType<MyService>().As<IMyService>();
        }
    }

    public class Program
    {
        public static void Main(string[] args)
        {
            var builder = WebApplication.CreateBuilder(args);
            // 在这里添加内置DI容器的服务配置
            // 例如，
            builder.Services.AddRazorPages();
            // 使用Autofac作为服务提供商
             builder.Host.UseServiceProviderFactory(new AutofacServiceProviderFactory())
                   .ConfigureContainer<ContainerBuilder>(containerBuilder =>
                   {
                       // 在这里向Autofac容器注册服务  此处使用模块方式注入
                       containerBuilder.RegisterModule<MyApplicationModule>();
                   });
             Add services to the container.
            //builder.Services.AddRazorPages();
          
            var app = builder.Build();

            // Configure the HTTP request pipeline.
            if (!app.Environment.IsDevelopment())
            {
                app.UseExceptionHandler("/Error");
            }
            app.UseStaticFiles();

            app.UseRouting();

            app.UseAuthorization();

            app.MapRazorPages();

            app.Run();
        }
    }
}

autofac 支持 命名 、key

using Autofac;
using Autofac.Extensions.DependencyInjection;

namespace WebApplication13
{
    public interface IMyService
    {
        string GetData();
    }

    public class MyService : IMyService
    {
        public string GetData()
        {
            return "Data from MyService---MyService";
        }
    }
    public class MyService2 : IMyService
    {
        public string GetData()
        {
            return "2222 from MyService---MyService2";
        }
    }
    public class MyApplicationModule : Module
    {
        protected override void Load(ContainerBuilder builder)
        {
            builder.RegisterType<MyService>().As<IMyService>();
            builder.RegisterType<MyService>().As<IMyService>().Named<IMyService>(typeof(MyService).Name);
            //builder.RegisterType<MyService>().As<IMyService>().Keyed<IMyService>(typeof(MyService).Name);
            builder.RegisterType<MyService2>().As<IMyService>().Named<IMyService>(nameof(MyService2));
        }
    }

    public class Program
    {
        public static void Main(string[] args)
        {
            var builder = WebApplication.CreateBuilder(args);
            // 在这里添加内置DI容器的服务配置
            // 例如，
            builder.Services.AddRazorPages();
            // 使用Autofac作为服务提供商
             builder.Host.UseServiceProviderFactory(new AutofacServiceProviderFactory())
                   .ConfigureContainer<ContainerBuilder>(containerBuilder =>
                   {
                       // 在这里向Autofac容器注册服务  此处使用模块方式注入
                       containerBuilder.RegisterModule<MyApplicationModule>();
                   });
             Add services to the container.
            //builder.Services.AddRazorPages();
          
            var app = builder.Build();

            // Configure the HTTP request pipeline.
            if (!app.Environment.IsDevelopment())
            {
                app.UseExceptionHandler("/Error");
            }
            app.UseStaticFiles();

            app.UseRouting();

            app.UseAuthorization();

            app.MapRazorPages();

            app.Run();
        }
    }
}