我正在构建一个应用程序并使用spotify。我设法开始并暂停一首歌......但我无法理解播放下一个按钮和playprevious按钮。有些人可以告诉我如何使用libspotify回放管理器来处理这些事件。我有一个播放列表视图,它将currentsong传递给我的songviewController ..如何从我的songViewController中调用下一首歌曲。这就是我如何称呼电流...
- (void)viewDidLoad
{
[super viewDidLoad];
self.playbackManager = [[SPPlaybackManager alloc] initWithPlaybackSession:[SPSession sharedSession]];
[self addObserver:self forKeyPath:@"currentSong.name" options:NSKeyValueObservingOptionInitial context:nil];
[self addObserver:self forKeyPath:@"currentSong.artists" options:NSKeyValueObservingOptionInitial context:nil];
[self addObserver:self forKeyPath:@"currentSong.album.cover.image" options:NSKeyValueObservingOptionInitial context:nil];
[SPTrack trackForTrackURL:self.currentSong.spotifyURL inSession:[SPSession sharedSession] callback:^(SPTrack *track) {
[self.playbackManager playTrack:track callback:^(NSError *error) {
if (error) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Cannot Play Track"
message:[error localizedDescription]
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil];
[alert show];
}
}];
}];
}
- (void)viewDidUnload
{
[self trackArtist];
[self trackTitle];
[self coverView];
[self currentSong];
[self removeObserver:self forKeyPath:@"currentSong.name"];
[self removeObserver:self forKeyPath:@"currentSong.artists"];
[self removeObserver:self forKeyPath:@"currentSong.album.cover.image"];
self.playbackManager.playbackSession.playing = NO;
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
if ([keyPath isEqualToString:@"currentSong.name"]) {
self.trackTitle.text = self.currentSong.name;
} else if ([keyPath isEqualToString:@"currentSong.artists"]) {
self.trackArtist.text = [[self.currentSong.artists valueForKey:@"name"] componentsJoinedByString:@","];
} else if ([keyPath isEqualToString:@"currentSong.album.cover.image"]) {
self.coverView.image = self.currentSong.album.cover.image;
} else {
[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
}
}
#pragma mark -
- (IBAction)playTrack:(id)sender {
if (self.playbackManager.isPlaying == NO) {
self.playbackManager.isPlaying = YES;
}
else if (self.playbackManager.playbackSession.playing == YES) {
self.playbackManager.isPlaying = NO;
}
}
-(IBAction)nextTrack:(id)sender
{
NSLog(@"index is : %i",nextIndex);
NSLog(@"playlistItems: %i",[currentPlaylist.items count] );
self.nextIndex++;
NSLog(@"index is : %i",nextIndex);
if (self.playbackManager.isPlaying == YES)
self.playbackManager.isPlaying = NO;
NSLog(@"0=yes 1=no : %i",_playbackManager.isPlaying);
SPPlaylistItem *item = [self.currentPlaylist.items objectAtIndex:self.nextIndex];
if (item.itemClass == [SPTrack class])
{
[self.playbackManager playTrack:(SPTrack*)item callback:^(NSError *error)
{
if (error)
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Cannot Play Track"
message:[error localizedDescription]
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil];
[alert show];
}
}
];
}
}
答案 0 :(得分:0)
CocoaLibSpotify以这种方式有点奇怪。要停止或“暂停”一首歌曲,您只需将playbackManager.isPlaying设置为no即可。停止当前歌曲后,您可以安全地在播放列表的下一首曲目上调用playTrack。它可能会像:
self.nextIndex++;
if (self.playbackManager.isPlaying)
self.playbackManager.isPlaying = NO;
SPPlaylistItem *playlistItem = [self.playlist.items objectAtIndex:self.nextIndex];
if (playlistItem.itemClass == [SPTrack class])
{
self.playbackManager playTrack:(SPtrack*)playlistItem.item callback:^(NSError *error) {
if (error)
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Cannot Play Track"
message:[error localizedDescription]
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil];
[alert show];
}
}
下一个索引将跟踪您在播放列表中的位置,例如
@property (assign) NSInteger nextIndex;
播放员是SPPlaylist的一个例子,例如
@property (nonatomic) SPPlaylist *playlist;
然后你可以在viewDidLoad中对它们进行一些初始化。 为方便起见,我可能会将playTrack方法包装在另一种方法中以停止代码重复。请注意playlistItem.item属性基本上是SPTrack
的100%