C#递归文件夹获得总大小

     /// <summary>       /// 递归文件夹获得总大小       /// </summary>       /// <param name="dir"></param>       /// <returns></returns>       public long countsize(System.IO.DirectoryInfo dir)       {           long size = 0;           FileInfo[] files = dir.GetFiles();           foreach (System.IO.FileInfo info in files)           {               size += info.Length;           }           DirectoryInfo[] dirs = dir.GetDirectories();           foreach (DirectoryInfo dirinfo in dirs)           {               size += countsize(dirinfo);           }           return size;       }