Decimal Number Conversion

using System;

class NumberConversion //#notcomplete
    {
        public NumberConversion()
        {
            int n = 1234;
            long bin = decToBinary(n);
            Console.WriteLine("The binary of {0} is {1}", n, bin);

            string hex = decToHex(n);
            Console.WriteLine("The Hex of {0} is {1}", n, hex);
        }

        long decToBinary(int n)
        {
            int rem;
            long result=0;
            int i = 1;
            while (n > 0)
            {
                rem = n % 2;
                result = result + rem * i;
                i = i * 10;
                n = n / 2;
            }
            return result;
        }

        string decToHex(int n)
        {
            int rem;
            string result="";
            int i = 1;
            while (n > 0)
            {
                rem = n % 16;
                String ch = getchar(rem);
                result = result + ch;
                //i = i * 10;
                n = n / 16;
            }
            Array.Reverse(result.ToCharArray());
            return result.ToString();
        }

        string getchar(int n)
        {
            string temp;
            if (n < 10)
                temp = n.ToString();
            else
            {
                switch (n)
                {
                    case 10:
                        temp = "A";
                        break;
                    case 11:
                        temp = "B";
                        break;
                    case 12:
                        temp = "C";
                        break;
                    case 13:
                        temp = "D";
                        break;
                    case 14:
                        temp = "E";
                        break;
                    case 15:
                        temp = "F";
                        break;
                    default:
                        temp = "X";
                        break;
                }
            }
            return temp;
        }
}