using System;

using System.Collections;

using System.Linq;

public class Program

{

    public static void Main()

    {

        string stringData = "AAAB"; // {000000} {000000} {000000} {000001}

        byte[] byteData = Convert.FromBase64String(stringData); // {00000000}{00000000}{00000001}

        BitArray bitData = new BitArray(byteData.Reverse().ToArray()); // {000000000000000000000001}

​

        Console.WriteLine("byteData");

        for(var i=0; i < byteData.Length; i++){ //bitData.Length is 32

            var bitValue = byteData[i];

            Console.WriteLine("{0} {1}", i, bitValue);

        }

        Console.WriteLine();

        Console.WriteLine("bitData");

        for(var i=0; i < bitData.Length; i++){ //bitData.Length is 32

            var bitValue = bitData[i];

            Console.WriteLine("{0} {1}", i, bitValue);

        }

        Console.WriteLine();

        Console.WriteLine("reversed");

        var reversed = bitData.Cast<bool>().Reverse().ToArray();

        for(var i=0; i < reversed.Length; i++){ //bitData.Length is 32

            var bitValue = reversed[i];

            Console.WriteLine("{0} {1}", i, bitValue);

        }

    }

}