定期删除文件夹中的文件——C#

        /// <summary>
        /// 定期清除文件
        /// </summary>
        /// <param name="fileDirect">文件夹</param>
        /// <param name="postFix">文件后缀</param>
        /// <param name="saveDay">保存天数</param>
        private void DeleteFile(string fileDirect, string postFix, int saveDay)

        {
            DateTime nowtime = DateTime.Now; //获取当前时间
            string[] files = Directory.GetFiles(fileDirect, postFix, SearchOption.AllDirectories);  //获取该目录下所有 .txt文件
            foreach (string file in files)
            {

                FileInfo fileInfo = new FileInfo(file);
                TimeSpan t = nowtime - fileInfo.CreationTime;  //当前时间  减去 文件创建时间
                int day = t.Days;
                if (day > saveDay)   //保存的时间 ；  单位：天
                {
                    File.Delete(file);  //删除超过时间的文件
                }
            }
        }

 pathLast = @"\" + day + ".xls"; //文件名
            pathHeard = Ini.IniReadValue("配置文件", "path"); //文件夹
            path = pathHeard + pathLast; //文件路径

            string deleteDay = Ini.IniReadValue("清除文件", "day"); //定期删除文件天数
            int deleteDayValue = -1;
            switch (deleteDay)
            {
                case "4":
                    deleteDayValue = -1;
                    break;
                case "3":
                    deleteDayValue = 3;
                    break;
                case "2":
                    deleteDayValue = 7;
                    break;
                case "1":
                    deleteDayValue = 15;
                    break;
                case "0":
                    deleteDayValue = 30;
                    break;
                default:
                    break;
            }

            if (deleteDayValue >= 0)
            {
                DeleteFile(pathHeard, "*.xls", deleteDayValue);
            }