C#創建唯一的訂單號, 考慮時間因素，

C#創建唯一的訂單號, 考慮時間因素，

主要是想把日期和其它因素考慮進來。

使用RNGCryptoServiceProvider類創建唯一的最多8位數字符串。

        private static string GetUniqueKey()
        {
            int maxSize = 8;
            int minSize = 5;
            char[] chars = new char[62];
            string a;
            a = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
            chars = a.ToCharArray();
            int size = maxSize;
            byte[] data = new byte[1];
            RNGCryptoServiceProvider crypto = new RNGCryptoServiceProvider();
            crypto.GetNonZeroBytes(data);
            size = maxSize;
            data = new byte[size];
            crypto.GetNonZeroBytes(data);
            StringBuilder result = new StringBuilder(size);
            foreach (byte b in data)
            {
                result.Append(chars[b % (chars.Length - 1)]);
            }
            return result.ToString();
        }

然後，

            for(int i = 0; i < 10; i++)
            {
                string str = string.Format("{0}{1}", DateTime.Now.ToString("yyyyMMddHHmmss"), GetUniqueKey());
                Console.WriteLine(str);
            }
            Console.ReadKey();