C# 获取最新文件

  public  class FileTimeInfo
    {
        public string FileName;  //文件名
        public DateTime FileCreateTime; //创建时间
    }

 /// <summary>
        /// 获取最新文件名
        /// </summary>
        /// <param name="dir">路径</param>
        /// <param name="ext">后缀名</param>
        /// <returns></returns>
        internal FileTimeInfo GetLatestFileTimeInfo(string dir, string ext)
        {
           string name = System.Configuration.ConfigurationSettings.AppSettings["name"];//匹配以什么开头的文件名
            List<FileTimeInfo> list = new List<FileTimeInfo>();
            DirectoryInfo d = new DirectoryInfo(dir);
            foreach (FileInfo fi in d.GetFiles(name+"*"))
            {
                if (fi.Extension.ToUpper() == ext.ToUpper())
                {
                    list.Add(new FileTimeInfo()
                    {
                        FileName = fi.FullName,
                        FileCreateTime = fi.CreationTime
                    });
                }
            }
            var qry = from x in list
                      orderby x.FileCreateTime
                      select x;
            return qry.LastOrDefault();
        }