Roman numerals are an ancient number system but still have uses in the modern world. Roman numerals are used to represent dates, analog clock faces and for indexing. This  C# code will show you how to convert a number into Roman numeral.

Code:

using System;
using System.Windows.Forms;


namespace IntegertoRomanNumeral
{
    public partial class FormConvertor : Form
    {
        public FormConvertor()
        {
            InitializeComponent();
        }

        private void btnconvert_Click(object sender, EventArgs e)
        {
            lblroman.ResetText();
            int number = Convert.ToInt32(txtroman.Text);

            if (number.ToString().Trim().Length == 0)
                return;

            if (number >= 4000)
            {
                MessageBox.Show("Please enter a number that is less than 4000.", 
                                this.Text, MessageBoxButtons.OK, MessageBoxIcon.Exclamation);

                txtroman.Focus();
                return;
            }

            String[] roman = new String[] { "M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I" };
            int[] decimals = new int[] { 1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1 };

            string romanvalue = String.Empty;

            for (int i = 0; i < 13; i++)
            {
                while (number >= decimals[i])
                {
                    number -= decimals[i];
                    romanvalue += roman[i];
                }
            }

            lblroman.Text = romanvalue;
        }
    }
}