static void convertToBinary(int n)
    {
        Stack<int> stack = new Stack<int>();
        stack.Push(n);
        // step 1 : Push the element on the stack
        while (n > 1)
        {
            n = n / 2;
            stack.Push(n);
        }

        // step 2 : Pop the element and print the value
        foreach(var val in stack)
        {
            Console.Write(val % 2);
        }
     }

        static void Main(string[] args) 
        {
        Console.WriteLine("Enter number for converting to binary numerical system!");
        int num = Convert.ToInt32(Console.ReadLine());
        int[] arr = new int[16];

        //for positive integers
        if (num > 0)
        {

            for (int i = 0; i < 16; i++)
            {
                if (num > 0)
                {
                    if ((num % 2) == 0)
                    {
                        num = num / 2;
                        arr[16 - (i + 1)] = 0;
                    }
                    else if ((num % 2) != 0)
                    {
                        num = num / 2;
                        arr[16 - (i + 1)] = 1;
                    }
                }
            }
            for (int y = 0; y < 16; y++)
            {
                Console.Write(arr[y]);
            }
            Console.ReadLine();
        }

        //for negative integers
        else if (num < 0)
        {
            num = (num + 1) * -1;

            for (int i = 0; i < 16; i++)
            {
                if (num > 0)
                {
                    if ((num % 2) == 0)
                    {
                        num = num / 2;
                        arr[16 - (i + 1)] = 0;
                    }
                    else if ((num % 2) != 0)
                    {
                        num = num / 2;
                        arr[16 - (i + 1)] = 1;
                    }
                }
            }

            for (int y = 0; y < 16; y++)
            {
                if (arr[y] != 0)
                {
                    arr[y] = 0;
                }
                else
                {
                    arr[y] = 1;
                }
                Console.Write(arr[y]);
            }
            Console.ReadLine();
        }           
    }

在c#中从任何经典基转换为任何基

string number = "100";
int fromBase = 16;
int toBase = 10;

string result = Convert.ToString(Convert.ToInt32(number, fromBase), toBase);

// result == "256"

支持的基数是2,8,10和16

http://zamirsblog.blogspot.com/2011/10/convert-decimal-to-binary-in-c.html

    public string DecimalToBinary(string data)
    {
        string result = string.Empty;
        int rem = 0;
        try
        {
            if (!IsNumeric(data))
                error = "Invalid Value - This is not a numeric value";
            else
            {
                int num = int.Parse(data);
                while (num > 0)
                {
                    rem = num % 2;
                    num = num / 2;
                    result = rem.ToString() + result;
                }
            }
        }
        catch (Exception ex)
        {
            error = ex.Message;
        }
        return result;
    }

class Program
{
    static void Main(string[] args)
    {
        var @decimal = 42;
        var binaryVal = ToBinary(@decimal, 2);

        var binary = "101010";
        var decimalVal = ToDecimal(binary, 2);

        Console.WriteLine("Binary value of decimal {0} is '{1}'", @decimal, binaryVal);
        Console.WriteLine("Decimal value of binary '{0}' is {1}", binary, decimalVal);
        Console.WriteLine();

        @decimal = 6;
        binaryVal = ToBinary(@decimal, 3);

        binary = "20";
        decimalVal = ToDecimal(binary, 3);

        Console.WriteLine("Base3 value of decimal {0} is '{1}'", @decimal, binaryVal);
        Console.WriteLine("Decimal value of base3 '{0}' is {1}", binary, decimalVal);
        Console.WriteLine();


        @decimal = 47;
        binaryVal = ToBinary(@decimal, 4);

        binary = "233";
        decimalVal = ToDecimal(binary, 4);

        Console.WriteLine("Base4 value of decimal {0} is '{1}'", @decimal, binaryVal);
        Console.WriteLine("Decimal value of base4 '{0}' is {1}", binary, decimalVal);
        Console.WriteLine();

        @decimal = 99;
        binaryVal = ToBinary(@decimal, 5);

        binary = "344";
        decimalVal = ToDecimal(binary, 5);

        Console.WriteLine("Base5 value of decimal {0} is '{1}'", @decimal, binaryVal);
        Console.WriteLine("Decimal value of base5 '{0}' is {1}", binary, decimalVal);
        Console.WriteLine();

        Console.WriteLine("And so forth.. excluding after base 10 (decimal) though :)");
        Console.WriteLine();


        @decimal = 16;
        binaryVal = ToBinary(@decimal, 11);

        binary = "b";
        decimalVal = ToDecimal(binary, 11);

        Console.WriteLine("Hexidecimal value of decimal {0} is '{1}'", @decimal, binaryVal);
        Console.WriteLine("Decimal value of Hexidecimal '{0}' is {1}", binary, decimalVal);
        Console.WriteLine();
        Console.WriteLine("Uh oh.. this aint right :( ... but let's cheat :P");
        Console.WriteLine();

        @decimal = 11;
        binaryVal = Convert.ToString(@decimal, 16);

        binary = "b";
        decimalVal = Convert.ToInt32(binary, 16);

        Console.WriteLine("Hexidecimal value of decimal {0} is '{1}'", @decimal, binaryVal);
        Console.WriteLine("Decimal value of Hexidecimal '{0}' is {1}", binary, decimalVal);

        Console.ReadLine();
    }


    static string ToBinary(decimal number, int @base)
    {
        var round = 0;
        var reverseBinary = string.Empty;

        while (number > 0)
        {
            var remainder = number % @base;
            reverseBinary += remainder;

            round = (int)(number / @base);
            number = round;
        }

        var binaryArray = reverseBinary.ToCharArray();
        Array.Reverse(binaryArray);

        var binary = new string(binaryArray);
        return binary;
    }

    static double ToDecimal(string binary, int @base)
    {
        var val = 0d;

        if (!binary.All(char.IsNumber))
            return 0d;

        for (int i = 0; i < binary.Length; i++)
        {
            var @char = Convert.ToDouble(binary[i].ToString());

            var pow = (binary.Length - 1) - i;
            val += Math.Pow(@base, pow) * @char;
        }

        return val;
    }
}

学习资源:

你需要知道的关于二进制的一切

包括算法转换十进制到二进制

原始的方法:

public string ToBinary(int n)
{
    if (n < 2) return n.ToString();

    var divisor = n / 2;
    var remainder = n % 2;

    return ToBinary(divisor) + remainder;
}