using System;

using System.Collections.Generic;

​

var random = new Random();

var array = new [] { 1, 2, 3 };

array.Shuffle(random);

foreach (var item in array) {

    Console.WriteLine(item);

}

​

public static class ListExtensions

{

    public static void Shuffle<T>(this IList<T> list, Random random)

    {

        for (var i = list.Count - 1; i > 0; i--)

        {

            int indexToSwap = random.Next(i + 1);

            (list[indexToSwap], list[i]) = (list[i], list[indexToSwap]);

        }

    }

}

​