public static ThumbnailDatabase Get(string folder)
    {
      lock (_cache)
      {
        for (int i = 0; i < _cache.Count; ++i)
        {
          if (String.Compare(_cache[i].Folder, folder, true) == 0) return _cache[i];
        }

        ThumbnailDatabase dbs = new ThumbnailDatabase(folder);
        _cache.Add(dbs);
        return dbs;
      }
    }
        public static ThumbnailDatabase Get(string folder)
        {
            lock (_cache)
            {
                for (int i = 0; i < _cache.Count; ++i)
                {
                    if (String.Compare(_cache[i].Folder, folder, true) == 0)
                    {
                        return(_cache[i]);
                    }
                }

                ThumbnailDatabase dbs = new ThumbnailDatabase(folder);
                _cache.Add(dbs);
                return(dbs);
            }
        }