public async Task AddNew(StopOperationToken stopToken)
{
IReadOnlyList <StorageFile> files = await GetStorageFolderFiles();
Song[] songs = Songs.ToArray();
IEnumerable <StorageFile> addFiles = files.Where(f => !songs.Any(s => s.Path == f.Path));
Song[] addSongs = (await GetSongsFromStoragefiles(addFiles, stopToken)).ToArray();
if (stopToken.IsStopped)
{
return;
}
if (addSongs.Length == 0)
{
return;
}
Songs.Change(null, addSongs);
}
public async Task Update(StopOperationToken stopToken)
{
Song[] songs = Songs.ToArray();
IReadOnlyList <StorageFile> files = await GetStorageFolderFiles();
IEnumerable <StorageFile> addFiles = files.Where(f => songs.All(s => s.Path != f.Path));
Song[] addSongs = (await GetSongsFromStoragefiles(addFiles, stopToken)).ToArray();
Song[] removeSongs = songs.Where(s => files.All(f => f.Path != s.Path)).ToArray();
if (stopToken.IsStopped)
{
return;
}
if (Songs.Count + addSongs.Length - removeSongs.Length == 0)
{
Parent.Remove(this);
return;
}
Songs.Change(removeSongs, addSongs);
}