Convert hex to binary

using System;
using System.Collections.Generic;
using System.Text;
//Write a program to convert hexadecimal numbers to binary numbers (directly).
class HexToBinary
{
    static void Main()
    {
        Console.WriteLine("Enter hex number : ");
        string convert = Console.ReadLine();
        convert = convert.ToLower();

        List<string> result = new List<string>();
        int temp = 0;
        for (int i = convert.Length - 1; i >= 0; i--)
        {
            temp = GetCharValue(convert, i);
            result.Add(GetBinaryWord(temp));
        }

        Console.WriteLine("Converted to binary:");
        for (int i = result.Count - 1; i >= 0; i--)
        {
            Console.Write(result[i]);
        }
        Console.WriteLine();
    }

    private static string GetBinaryWord(int temp)
    {
        StringBuilder builder = new StringBuilder();

        for (int j = 0; j < 4; j++)
        {
            if ((temp & 1) == 1)
            {
                builder.Insert(0, 1);
            }
            else
            {
                builder.Insert(0, 0);
            }
            temp /= 2;
        }
        return builder.ToString();
    }

    private static int GetCharValue(string convert, int position)
    {
        if (convert[position] <= '9')
        {
            return convert[position] - '0';
        }
        else
        {
            return convert[position] - 'a' + 10;
        }

    }
}