using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        List<Message> messages = new List<Message>

        {

            new Message(10),

            new Message(7),

            new Message(1),

            new Message(2),

            new Message(5)

        };

        foreach (var message in messages.OrderBy(message => { Console.WriteLine("Outside: " + message.Num); return message.Num; }))

        {

            Console.WriteLine("Inside: " + message.Num);

        }

    }

}

​

public class Message

{

    public Message(int num)

    {

        Num = num;

    }

​

    public int Num { get; set; }

}