using System;

using System.ComponentModel.DataAnnotations;

using Microsoft.Extensions.DependencyInjection;

using Microsoft.Extensions.Options;

​

public class Foo 

{

    [Range(0, 100)]

    public int Bar { get; set; }

}

​

public class Program

{

    public static void Main()

    {

        Action<Foo> optionsBuilder = options => options.Bar = 101;

        var services = new ServiceCollection();

        services

            .AddOptions<Foo>()

            .Configure(optionsBuilder)

            .ValidateDataAnnotations();

        var options = services

            .BuildServiceProvider()

            .GetRequiredService<IOptions<Foo>>()

            .Value;

    }

}