3rdpartylibs/fastreports.wpf/FastReport.Base/Functions/Roman.cs

using System;
using System.Text;
using System.Collections;
using System.Collections.Generic;

namespace FastReport.Functions
{
    /// <summary>
    /// Based on code of Stefan Böther,  xprocs@hotmail.de
    /// </summary>
    internal static class Roman
    {
        private static int MAX = 3998;
        private static string[,] romanDigits = new string[,] {
        {"M",      "C",    "X",    "I"    },
        {"MM",     "CC",   "XX",   "II"   },
        {"MMM",    "CCC",  "XXX",  "III"  },
        {null,     "CD",   "XL",   "IV"   },
        {null,     "D",    "L",    "V"    },
        {null,     "DC",   "LX",   "VI"   },
        {null,     "DCC",  "LXX",  "VII"  },
        {null,     "DCCC", "LXXX", "VIII" },
        {null,     "CM",   "XC",   "IX"   }};

        public static string Convert(int value)
        {
            if (value > MAX)
                throw new ArgumentOutOfRangeException("value");

            StringBuilder result = new StringBuilder(15);

            for (int index = 0; index < 4; index++)
            {
                int power = (int)Math.Pow(10, 3 - index);
                int digit = value / power;
                value -= digit * power;
                if (digit > 0)
                    result.Append(romanDigits[digit - 1, index]);
            }

            return result.ToString();
        }
    }
}