ラムダ式サンプル

Faile.cs

using System;
using System.Collections.Generic;

namespace BatchConsole
{
    class Program
    {

        static void Main(string[] args)
        {
            var list = new List<Action>();

            var array = new[] { 1,2,3 };
            foreach (var val in array)
            {
                Action act = () => Console.WriteLine(val);
                list.Add(act);
            }

            foreach (var act in list)
            {
                act(); //常に 3 が出力される
            }


            Console.ReadKey();
        }
    }
}

Success.cs

using System;
using System.Collections.Generic;

namespace BatchConsole
{
    class Program
    {

        static void Main(string[] args)
        {
            var list = new List<Action>();

            var array = new[] { 1, 2, 3 };
            foreach (var temp in array)
            {
                var val = temp;
                Action act = () => Console.WriteLine(val);
                list.Add(act);
            }

            foreach (var act in list)
            {
                act(); //1,2,3と出力される
            }


            Console.ReadKey();
        }
    }
}