C# 判断字符串是否符合十六进制，八进制，二进制和十进制整数格式的正则表达式

　　　　  /// <summary>
        /// 判断是否十六进制格式字符串
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public bool IsHexadecimal(string str)
        {
            const string PATTERN = @"[A-Fa-f0-9]+$";
            return System.Text.RegularExpressions.Regex.IsMatch(str, PATTERN);
        }

        /// <summary>
        /// 判断是否八进制格式字符串
        /// </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>
        /// 判断是否二进制格式字符串
        /// </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>
        /// 判断是否十进制格式字符串
        /// </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);
        }