无法使用kMRMediaRemoteNowPlayingInfoArtworkData从Objective C中的Spotify获取专辑图片

Question

我正在调整一个在Mac TouchBar上显示窗口小部件的分支TouchBar应用程序，并试图让专辑图片显示在NowPlaying窗口小部件上。这是project。

目前，我对这段代码有一些问题：

- (void)updateInfo
{
    MRMediaRemoteGetNowPlayingInfo(dispatch_get_main_queue(),
        ^(NSDictionary *info)
        {
            NSString *album = [info objectForKey:kMRMediaRemoteNowPlayingInfoAlbum];
            NSString *artist = [info objectForKey:kMRMediaRemoteNowPlayingInfoArtist];
            NSString *title = [info objectForKey:kMRMediaRemoteNowPlayingInfoTitle];
            NSData *artworkData = [info objectForKey:kMRMediaRemoteNowPlayingInfoArtworkData];
        
        NSImage *albumart = nil;
        if (nil != artworkData && ![artworkData isEqual:[NSNull null]])
        {
            albumart = [[NSImage alloc] initWithData:artworkData];
        }
        
        if (nil != albumart)
        {
            self.appIcon = albumart;
        }
        
        if (self.album != album || self.artist != artist || self.title != title || self.albumArt != albumart)
        {
            self.album = album;
            self.artist = artist;
            self.title = title;
            self.albumArt = albumart;

            [[NSNotificationCenter defaultCenter]
                postNotificationName:NowPlayingInfoNotification
                object:self];
        }
    });
}

我遇到的主要问题是，专辑画面数据在歌曲开始后只显示了大约半秒，之后就消失了。我的理论是，使用kMRMediaRemoteNowPlayingInfoArtworkData来获取艺术作品数据是错误的，但我可能错了。

Answer 1

发现如果从通知中心拉取数据，Spotify和Music不会立即更新其专辑画面数据。解决方案是添加大约50ms的延迟。