随机码的生成

通常使用DateTime的Tick作为Random函数的Seek，在本机测试没有问题，但是问题来了，在服务器上时，cpu运行很快，当连续的取随机数时，它们的Tick是一样的，因此产生的随机数也一样，代码如下：

 private static readonly string[] _allChar = new string[] { "0","1","2","3","4","5","6","7","8","9",
            "A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","W","X","Y","Z"};

        /// <summary>
        /// 生成随机密码，由字符和数字组成
        /// </summary>
        /// <param name="length"></param>
        /// <returns></returns>
        public static string CreatePass(int length)
        {
            StringBuilder sbPass = new StringBuilder();
            Random seekRand = new Random(unchecked((int)DateTime.Now.Ticks));
            //生成起始序列值
            int beginSeek = (int)seekRand.Next(0, Int32.MaxValue - 10000 * length);
            int[] seeks = new int[length];
            for (int i = 0; i < length; i++)
            {
                beginSeek += 10000;
                seeks[i] = beginSeek;
            }

            //生成并抽取随机数字
            for (int i = 0; i < length; i++)
            {
                Random rand = new Random(seeks[i]);
                sbPass.Append(_allChar[rand.Next(35)]);
            }
            return sbPass.ToString();
        }

　　如何解决产生的随机数一样呢？关键点在于Random的Seek，使用一个不重复的Seek即可，所以想到了Guid的HashCode：

  Random seekRand = new Random(Guid.NewGuid().GetHashCode());

　　效果不错~！

前面5个是后来生成的随机码，后面5个是之前生成的随机码