判断是否为ID串

/// <summary>
        /// 判断是否为ID串。
        /// </summary>
        /// <example>
        /// 1,2,3,4,5,6,7
        /// </example>
        /// <param name="intList">要判断的字符串</param>
        /// <returns></returns>
        public static bool IsIntParamsString(string paramsString)
        {
            if (string.IsNullOrEmpty(paramsString) || paramsString.StartsWith(Separator) || paramsString.EndsWith(Separator))
            {
                return false;
            }
            bool flag = false;
            char separator = Separator[0];
            for (int i = 0; i < paramsString.Length; i++)
            {
                char c = paramsString[i];
                if (c >= '0' && c <= '9')
                {
                    flag = false;
                }
                else if (c == separator)
                {
                    if (flag)
                    {
                        return false;
                    }
                    else
                    {
                        flag = true;
                    }
                }
                else
                {
                    return false;
                }
            }
            return true;
        }