MPMusicPlayerController setQueue 和 noPlayingItem 默认为索引 0

Question

当我尝试更改 MPMusicPlayerController 的队列并设置 nowPlayingItem 时，播放器总是转到队列中的第一项。文档说如果我想设置队列中的当前位置，我应该将 nowPlayingItem 设置为队列中的 MPMediaItem。我做错了什么吗？

MPMusicPlayerController *player = [MPMusicPlayerController systemMusicPlayer];
    [player setRepeatMode:MPMusicRepeatModeNone];
    [player setShuffleMode:MPMusicShuffleModeOff];
    [player pause];
    MPMediaItemCollection *collection = [MPMediaItemCollection collectionWithItems:[[HMFAudioManager sharedManager] playlist]];
    [player setQueueWithItemCollection:collection];
    MPMediaItem *selectedItem = collection.items[indexPath.row];
    NSLog(@"selected item                          - %@",selectedItem.title);
    NSLog(@"manager's current now playing item     - %@",[[HMFAudioManager sharedManager] nowPlayingItem].title);
    [[HMFAudioManager sharedManager] setNowPlayingItem:collection.items[indexPath.row]];
    NSLog(@"manager's new now playing item         - %@",[[HMFAudioManager sharedManager] nowPlayingItem].title);
    player.nowPlayingItem = collection.items[indexPath.row];
    player.currentPlaybackTime = [collection.items[indexPath.row] bookmarkTime];
    [player play];
    NSLog(@"player's now playing                   - %@",player.nowPlayingItem.title);
    NSLog(@"manager's new now playing item         - %@",selectedItem.title);
    [self dismissViewControllerAnimated:YES completion:nil];

日志-

2015-08-07 16:51:42.003 Undulib[1986:487940] selected item                          - Star Wars: The Empire Strikes Back
2015-08-07 16:51:42.004 Undulib[1986:487940] manager's current now playing item     - Star Wars: A New Hope
2015-08-07 16:51:42.005 Undulib[1986:487940] manager's new now playing item         - Star Wars: The Empire Strikes Back
2015-08-07 16:51:42.238 Undulib[1986:487940] player's now playing                   - Star Wars: A New Hope
2015-08-07 16:51:42.238 Undulib[1986:487940] manager's new now playing item         - Star Wars: The Empire Strikes Back

Answer 1

停止播放器而不是暂停播放器解决了问题。

MPMusicPlayerController setQueue 和 noPlayingItem 默认为索引 0

MPMusicPlayerController setQueue and noPlayingItem defaults to index 0

mpmediaitem

mpmediaitemcollection

mpmusicplayercontroller