//利用时间和Guid作为种子产生随机数private string GenerateUniqueID(){      System.Text.StringBuilder sb = new System.Text.StringBuilder();      string str1 = DateTime.Now.ToString("yyyyMMddHHmmss");      Random d = new Random(Guid.NewGuid().GetHashCode());      string str2 = d.Next(10000, 100000).ToString();      return sb.Append(str1).Append(str2).ToString(); }
　　

       //利用时间和RNGCryptoServiceProvider产生        public static string GenerateOrderNumber()        {            string strDateTimeNumber = DateTime.Now.ToString("yyyyMMddHHmmssms");            string strRandomResult = NextRandom(1000, 1).ToString();            return strDateTimeNumber + strRandomResult;        }        /// <summary>        /// 参考：msdn上的RNGCryptoServiceProvider例子        /// </summary>        /// <param name="numSeeds"></param>        /// <param name="length"></param>        /// <returns></returns>        private static int NextRandom(int numSeeds, int length)        {            // Create a byte array to hold the random value.              byte[] randomNumber = new byte[length];            // Create a new instance of the RNGCryptoServiceProvider.              System.Security.Cryptography.RNGCryptoServiceProvider rng = new System.Security.Cryptography.RNGCryptoServiceProvider();            // Fill the array with a random value.              rng.GetBytes(randomNumber);            // Convert the byte to an uint value to make the modulus operation easier.              uint randomResult = 0x0;            for (int i = 0; i < length; i++)            {                randomResult |= ((uint)randomNumber[i] << ((length - 1 - i) * 8));            }            return (int)(randomResult % numSeeds) + 1;        }