生成类似Guid字符串

/*
 * 基本思路：本字符串共20位，采用14位数字+6位字母组合
 * 数字部分：系统当前时间
 * 字母部分：26个英文字母
 * 随即组合：字母随即插入数字部分
 */

        private static string CreateString()
        {
            string[] words = new string[] { "A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
            string str = DateTime.Now.ToLocalTime().ToString("yyyyMMddHHMMss");
            Random random = new Random();
            str = words[random.Next(0, 25)] + str+words[random.Next(0,25)];
            for (int i = 0; i < 4; i++)
            {
                str = str.Insert(random.Next(1,18),words[random.Next(0,25)]);
            }
            return str;
        }