.net工具类——获取编码（生成随机数）

 .net工具类——获取编码（生成随机数）

1. GetNumber：获取编码。年月日+八位随机数
2. GetNumber2：获取编码。随机数
3. GenerateCode：获取编码。包含大写英文和数字、去掉字母I和O
4. GetCodePerfix：获取编码的前缀，年月（格式如：AK，表示2018年11月）

        /// <summary>
        /// 获取编码。年月日+八位随机数
        /// </summary>
        /// <returns></returns>
        public static string GetNumber()
        {
            byte[] buffer = Guid.NewGuid().ToByteArray();
            var ram = BitConverter.ToInt64(buffer, 0);
            var str = string.Format("{0}{1}", Utils.GetRamCode2(), ram.ToString().Substring(0, 8));
            return str;

            //var str = string.Format("{0}{1}", Utils.GetRamCode2(), Utils.Number(6, true));
            //return str;
        }

        /// <summary>
        /// 获取编码。随机数
        /// </summary>
        /// <returns></returns>
        public static string GetNumber2(int Length)
        {
            byte[] buffer = Guid.NewGuid().ToByteArray();
            var ram = BitConverter.ToInt64(buffer, 0);
            var str = string.Format("{0}", ram.ToString().Substring(0, Length));
            return str;
        }

        /// <summary>
        /// 获取编码。年月日+八位随机数
        /// </summary>
        /// <returns></returns>
        public static string GetNumber(List<string> listNumber)
        {
            string Number = GetNumber();
            int i = 0;
            while (true)
            {
                ++i;
                if (listNumber.Contains(Number))
                {
                    Number = GetNumber();
                }
                else
                {
                    break;
                }

                if (i > 10)
                {
                    LogHelper.WriteLog("GetNumber已经执行了{i}次！");
                }

            }
            return Number;
        }

        /// <summary>
        /// 获取编码。随机数
        /// </summary>
        /// <returns></returns>
        public static string GetNumber2(int Length, List<string> listNumber)
        {
            string Number = GetNumber2(Length);
            int i = 0;
            while (true)
            {
                ++i;
                if (listNumber.Contains(Number))
                {
                    Number = GetNumber2(Length);
                }
                else
                {
                    break;
                }

                if (i > 10)
                {
                    LogHelper.WriteLog("GetNumber已经执行了{i}次！");
                }

            }
            return Number;
        }

        /// <summary>
        /// 包含大写英文和数字、去掉字母I和O
        /// </summary>
        private static char[] constant =
        {
        '0','1','2','3','4','5','6','7','8','9',
        'A','B','C','D','E','F','G','H','J','K','L','M','N','P','Q','R','S','T','U','V','W','X','Y','Z'
        };

        /// <summary>
        /// 获取编码。包含大写英文和数字、去掉字母I和O
        /// </summary>
        /// <returns></returns>
        public static string GenerateCode(int Length)
        {
            Thread.Sleep(10);
            StringBuilder newRandom = new StringBuilder(34);
            Random rd = new Random();
            for (int i = 0; i < Length; i++)
            {
                newRandom.Append(constant[rd.Next(34)]);
            }
            return newRandom.ToString();
        }

        /// <summary>
        /// 获取编码。包含大写英文和数字、去掉字母I和O
        /// </summary>
        /// <returns></returns>
        public static string GenerateCode(int Length, List<string> listNumber)
        {
            string Number = GenerateCode(Length);
            int i = 0;
            while (true)
            {
                ++i;
                if (listNumber.Contains(Number))
                {
                    Number = GenerateCode(Length);
                }
                else
                {
                    break;
                }
                if (i > 10)
                {
                    LogHelper.WriteLog($"GenerateCode已经执行了{i}次！");
                }
            }
            return Number;
        }

        /// <summary>
        /// 获取编码的前缀，年月（格式如：AK，表示2018年11月）
        /// </summary>
        /// <returns></returns>
        public static string GetCodePerfix()
        {
            var dtNow = DateTime.Now;
            int thisYear = dtNow.Year;
            int thisMonth = dtNow.Month;

            int year = 'A' + (thisYear - 2018);//从2018年开始
            int month = 'A' + (thisMonth - 1);//从一月开始

            return (char)year + "" + (char)+month;
        }