/// <summary>
        /// 根据条件获取相关后缀的文件  没有子文件的
        /// </summary>
        /// <param name="path"></param>
        /// <param name="suffix"></param>
        /// <returns></returns>
        private List<FileModel> getFiles(string path,  string suffix)
        {

            List<FileModel> fileList = new List<FileModel>(); //这个model自己创建

            if (!Directory.Exists(path))//如果路径不存在则创建路径
            {
                Directory.CreateDirectory(path);
            }
            string filename;
            DirectoryInfo dir = new DirectoryInfo(path);
            FileInfo[] file = dir.GetFiles().OrderByDescending(n => n.LastWriteTime).ToArray();
       
            foreach (FileInfo f in file)
            {
                filename = f.FullName;
                if (filename.EndsWith(suffix))//判断文件后缀，并获取指定格式的文件全路径增添至fileList
                {
                    FileModel model = new FileModel();
                    model.FullName = f.FullName;
                    model.MAOPERATIONTIME = DateTime.Now;
                    model.Name = f.Name;
                    fileList.Add(model);
                }
            }
            return fileList;
        }