C#實作類別似Excel自動填滿儲存格，後面的數字累加

class Program    {        static void Main(string[] args)        {            Console.WriteLine(Next("abc123def345ghi"));            Console.Read();        }        private static string Next(string s)        {            if (!isNumber(s.Substring(s.Length-1,1)))                s = s + "0";            MatchCollection coll = Regex.Matches(s, @"\d+");            Match m = coll[coll.Count - 1];            return s.Substring(0, m.Index) + NextNum(m.Value);        }        private static string NextNum(string s)        {            char[] cs = s.ToCharArray();            for (int i = s.Length - 1; i >= 0; i--)            {                if (!NextChar(ref   cs[i])) break;            }                       string re = new string(cs);            if (Int32.Parse(re) == 0)                re = "1" + re;            return re;        }        private static bool NextChar(ref   char c)        {            string p = "0123456789０１２３４５６７８９";            int n = p.IndexOf(c);            c = p[(n + 1) % 10 + 10 * (n / 10)];            return (n == 9 || n == 19);        }        public static bool isNumber(string str)        {            Regex r = new Regex(@"^\d+(\.)?\d*$");            if (r.IsMatch(str))            {                return true;            }            else            {                return false;            }        }