Dynamic orderBy

gistfile1.txt

using System;
using System.Collections.Generic;
using System.Linq;

namespace DelegateTest
{
    class Pet
    {
        public string Name { get; set; }
        public int Age { get; set; }
    }

    enum Key
    {
        Name,
        Age
    }

    class Program
    {
        public static void Main()
        {
            Key givenkey = Key.Age;
            Pet[] pets = { new Pet { Name="Barley", Age=8 },
                       new Pet { Name="Boots", Age=4 },
                       new Pet { Name="Whiskers", Age=1 } };


            Console.Write("A sortuje po wieku, wszystko inne po Nazwie\n");
            ConsoleKeyInfo input = Console.ReadKey();
            Console.WriteLine("");

            givenkey = (input.KeyChar == 'A') ? Key.Age : Key.Name;

            Func<Pet, Object> orderByFunct = generate(givenkey);

            IEnumerable<Pet> query = pets.OrderBy(orderByFunct);

            foreach (Pet pet in query)
            {
                Console.WriteLine("{0} - {1}", pet.Name, pet.Age);
            }

            Console.ReadKey();
        }

        public static Func<Pet, object> generate(Key field)
        {
            Func<Pet, object> a;

            if (field == Key.Age)
            {

                a = (source) => { return source.Age; };
            }
            else
            {
                a = (source) => { return source.Name; };
            }
            return a;
        }
    }
}