using System;

using Microsoft.Extensions.DependencyInjection;

public class Program

{

    public static void Main()

    {

        using (var rootServiceProvider = BuildServices())

        using (var rootScope = rootServiceProvider.CreateScope())

        {

            var provider = rootScope.ServiceProvider;

            var genericStr1 = provider.GetRequiredService<IGenericTest<string>>();

            var genericStr2 = provider.GetRequiredService<IGenericTest<string>>();

            var genericInt = provider.GetRequiredService<IGenericTest<int>>();

​

            genericStr1.Value = "test";

            Console.WriteLine(genericStr2.Value); // == "test"

            Console.WriteLine(genericInt.Value.ToString()); // == 0 == default(int);

        }

    }

​

    public static ServiceProvider BuildServices(Action<IServiceCollection> configure = null) {

        var services = new ServiceCollection();

        services.AddSingleton(typeof(IGenericTest<>), typeof(GenericTest<>));

        if (configure != null) {

            configure(services);

        }

        return services.BuildServiceProvider();

    }

}

​

public interface IGenericTest<T>

{

    T Value { get; set; }

}

public class GenericTest<T> : IGenericTest<T>

{

    public T Value {get; set; }

}