C# 判斷字符串是否符合十六進制，八進制，二進制和十進制整數格式的正則表達式

        /// <summary>
        /// 判斷是否十六進制格式字符串
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public bool IsHexadecimal(string str)
        {
            const string PATTERN = @"([A-F][a-f][0-9])+$";
            return System.Text.RegularExpressions.Regex.IsMatch(str, PATTERN);
        }

        /// <summary>
        /// 判斷是否八進制格式字符串
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public bool IsOctal(string str)
        {
            const string PATTERN = @"[0-7]+$";
            return System.Text.RegularExpressions.Regex.IsMatch(str, PATTERN);
        }

        /// <summary>
        /// 判斷是否二進制格式字符串
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public bool IsBinary(string str)
        {
            const string PATTERN = @"[0-1]+$";
            return System.Text.RegularExpressions.Regex.IsMatch(str, PATTERN);
        }

        /// <summary>
        /// 判斷是否十進制格式字符串
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public bool IsDecimal(string str)
        {
            const string PATTERN = @"[0-9]+$";
            return System.Text.RegularExpressions.Regex.IsMatch(str, PATTERN);
        }