using System;

using Microsoft.Extensions.DependencyInjection;

public class Program

{

    public static void Main()

    {

        var serviceCollection = new ServiceCollection();

        serviceCollection.AddScoped<A>();

        serviceCollection.AddTransient<B>();

​

        var sp = serviceCollection.BuildServiceProvider();

        var scope = sp.CreateScope();

        var b = scope.ServiceProvider.GetRequiredService<B>();

        var a = sp.GetRequiredService<A>();

        var b2 = sp.GetRequiredService<B>();

        Console.WriteLine();

    }

}

​

class A

{

}

​

class B(A a)

{

    public override string ToString()

    {

        return a.ToString();

    }

}