.net工具類——隨機生成

1. GetRamCode：生成日期隨機碼（年月日時分秒毫秒）
2. Number：生成隨機數字
3. GetCheckCode：生成隨機字母字串(數字字母混和)
4. GetOrderNumber：根據日期和隨機碼生成訂單號
5. Next

     
        #region 生成日期隨機碼

        /// <summary>
        /// 生成日期隨機碼（年月日時分秒毫秒）
        /// </summary>
        /// <returns></returns>
        public static
 
 string GetRamCode()
        {
            #region
            return DateTime.Now.ToString("yyyyMMddHHmmssffff");
            #endregion 生成日期隨機碼
        }

        /// <summary>
        /// 生成日期隨機碼（年月日）
        /// </summary>
        /// <returns></returns>
        public static string GetRamCode2()
        {
            
 
#region
            return DateTime.Now.ToString("yyyyMMdd");
            #endregion 生成日期隨機碼
        }

        #endregion

        #region 生成隨機字母或數字

        /// <summary>
        /// 生成隨機數字
        /// </summary>
        /// <param name="length">生成長度</param>
        /// <returns></returns>
 

        public static string Number(int Length)
        {
            return Number(Length, false);
        }

        /// <summary>
        /// 生成隨機數字
        /// </summary>
        /// <param name="Length">生成長度</param>
        /// <param name="Sleep">是否要在生成前將當前執行緒阻止以避免重複</param>
        /// <returns></returns>
        public static string Number(int Length, bool Sleep)
        {
            if (Sleep)
                System.Threading.Thread.Sleep(3);
            string result = "";
            System.Random random = new Random();
            for (int i = 0; i < Length; i++)
            {
                result += random.Next(10).ToString();
            }
            return result;
        }

        /// <summary>
        /// 生成隨機字母字串(數字字母混和)
        /// </summary>
        /// <param name="codeCount">待生成的位數</param>
        public static string GetCheckCode(int codeCount)
        {
            string str = string.Empty;
            int rep = 0;
            long num2 = DateTime.Now.Ticks + rep;
            rep++;
            Random random = new Random(((int)(((ulong)num2) & 0xffffffffL)) | ((int)(num2 >> rep)));
            for (int i = 0; i < codeCount; i++)
            {
                char ch;
                int num = random.Next();
                if ((num % 2) == 0)
                {
                    ch = (char)(0x30 + ((ushort)(num % 10)));
                }
                else
                {
                    ch = (char)(0x41 + ((ushort)(num % 0x1a)));
                }
                str = str + ch.ToString();
            }
            return str;
        }

        /// <summary>
        /// 根據日期和隨機碼生成訂單號
        /// </summary>
        /// <returns></returns>
        public static string GetOrderNumber()
        {
            string num = DateTime.Now.ToString("yyMMddHHmmss");//yyyyMMddHHmmssms
            return num + Number(2).ToString();
        }

        private static int Next(int numSeeds, int length)
        {
            byte[] buffer = new byte[length];
            System.Security.Cryptography.RNGCryptoServiceProvider Gen = new System.Security.Cryptography.RNGCryptoServiceProvider();
            Gen.GetBytes(buffer);
            uint randomResult = 0x0;//這裡用uint作為生成的隨機數
            for (int i = 0; i < length; i++)
            {
                randomResult |= ((uint)buffer[i] << ((length - 1 - i) * 8));
            }
            return (int)(randomResult % numSeeds);
        }

        #endregion