生成指定长度随机字符串

       

 /// <summary>
        /// 生成指定长度随机字符串（由大写字母组成）
        /// </summary>
        public static string GenerateRandomFilename(int len)
        {
            char[] chars = new char[]{'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'};
            Random random = new Random(DateTime.Now.Millisecond);
            string fileName = String.Empty;
            for (int i = 0; i < len; i++)
            {
                int index = random.Next(0, 26);
                fileName += chars[index];
            }
            return fileName;
        }