addMusic 和playMusic(AVAudioPlayer)-白红宇

addMusic 和playMusic(AVAudioPlayer)

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发布时间：2019-06-28

本文共 6907 字，大约阅读时间需要 23 分钟。

1 -setupApplicationAudio//声音文件及播放器的准备 2 选择播放器 3 - (void) updatePlayerQueueWithMediaCollection: (MPMediaItemCollection *) mediaItemCollection//更新播放器列表

复制代码

1 - (void) setupApplicationAudio {
     2          3         // Gets the file system path to the sound to play.  4         NSString *soundFilePath = [[NSBundle mainBundle]pathForResource: @"sound"  ofType:@"caf" ];  6         // Converts the sound's file path to an NSURL object  7         NSURL *newURL = [[NSURL alloc] initFileURLWithPath: soundFilePath];  8         self.soundFileURL = newURL;  9         [newURL release]; 10         // Registers this class as the delegate of the audio session. 11         [[AVAudioSession sharedInstance] setDelegate: self]; 12         13         // The AmbientSound category allows application audio to mix with Media Player 14 // audio. The category also indicates that application audio should stop playing 15 // if the Ring/Siilent switch is set to "silent" or the screen locks. 16         [[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryAmbient error: nil]; 17         // Registers the audio route change listener callback function 18         AudioSessionAddPropertyListener ( 19                 kAudioSessionProperty_AudioRouteChange, 20                 audioRouteChangeListenerCallback, 21                 self 22         ); 23         // Activates the audio session. 24         25         NSError *activationError = nil; 26         [[AVAudioSession sharedInstance] setActive: YES error: &activationError]; 27         // Instantiates the AVAudioPlayer object, initializing it with the sound 28         AVAudioPlayer *newPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL: soundFileURL error: nil]; 29         self.appSoundPlayer = newPlayer; 30         [newPlayer release]; 31         32         // "Preparing to play" attaches to the audio hardware and ensures that playback 33 //                starts quickly when the user taps Play 34         [appSoundPlayer prepareToPlay]; 35         [appSoundPlayer setVolume: 1.0]; 36         [appSoundPlayer setDelegate: self]; 37 }

1 //选择播放器  2 if ([self useiPodPlayer]) {
    3          4        [self setMusicPlayer: [MPMusicPlayerController iPodMusicPlayer]];  5                  6         if ([musicPlayer nowPlayingItem])

　　　　　　{
    7                  8              navigationBar.topItem.leftBarButtonItem.enabled = YES;  9                         10 　　　　　　　 // Update the UI to reflect the now-playing item. 11              [self handle_NowPlayingItemChanged: nil]; 12                         13              if ([musicPlayer playbackState] == MPMusicPlaybackStatePaused)

　　　　　　　　  {
   14                     navigationBar.topItem.leftBarButtonItem = playBarButton; 15              } 16        } 17                 18  }

　　　　else {
   19         20           [self setMusicPlayer: [MPMusicPlayerController applicationMusicPlayer]]; 21                 22            // By default, an application music player takes on the shuffle and repeat modes 23            // of the built-in iPod app. Here they are both turned off. 24           [musicPlayer setShuffleMode: MPMusicShuffleModeOff]; 25           [musicPlayer setRepeatMode: MPMusicRepeatModeNone]; 26        }

1 - (void) updatePlayerQueueWithMediaCollection: (MPMediaItemCollection *) mediaItemCollection {
    2         // Configure the music player, but only if the user chose at least one song to play  3         if (mediaItemCollection) {
    4                 // If there's no playback queue yet...  5                 if (userMediaItemCollection == nil) {
    6                  7                         // apply the new media item collection as a playback queue for the music player  8                         [self setUserMediaItemCollection: mediaItemCollection];  9                         [musicPlayer setQueueWithItemCollection: userMediaItemCollection]; 10                         [self setPlayedMusicOnce: YES]; 11                         [musicPlayer play]; 12                 // Obtain the music player's state so it can then be 13 //                restored after updating the playback queue. 14                 } else {
   15                         // Take note of whether or not the music player is playing. If it is 16 //                it needs to be started again at the end of this method. 17                         BOOL wasPlaying = NO; 18                         if (musicPlayer.playbackState == MPMusicPlaybackStatePlaying) {
   19                                 wasPlaying = YES; 20                         } 21                         22                         // Save the now-playing item and its current playback time. 23                         MPMediaItem *nowPlayingItem                        = musicPlayer.nowPlayingItem; 24                         NSTimeInterval currentPlaybackTime        = musicPlayer.currentPlaybackTime; 25                         // Combine the previously-existing media item collection with the new one 26                         NSMutableArray *combinedMediaItems        = [[userMediaItemCollection items] mutableCopy]; 27                         NSArray *newMediaItems                                = [mediaItemCollection items]; 28                         [combinedMediaItems addObjectsFromArray: newMediaItems]; 29                         30                         [self setUserMediaItemCollection: [MPMediaItemCollection collectionWithItems: (NSArray *) combinedMediaItems]]; 31                         [combinedMediaItems release]; 32                         // Apply the new media item collection as a playback queue for the music player. 33                         [musicPlayer setQueueWithItemCollection: userMediaItemCollection]; 34                         35                         // Restore the now-playing item and its current playback time. 36                         musicPlayer.nowPlayingItem                        = nowPlayingItem; 37                         musicPlayer.currentPlaybackTime                = currentPlaybackTime; 38                         39                         // If the music player was playing, get it playing again. 40                         if (wasPlaying) {
   41                                 [musicPlayer play]; 42                         } 43                 } 44                 // Finally, because the music player now has a playback queue, ensure that 45 //                the music play/pause button in the Navigation bar is enabled. 46                 navigationBar.topItem.leftBarButtonItem.enabled = YES; 47                 [addOrShowMusicButton        setTitle: NSLocalizedString (@"Show Music", @"Alternate title for 'Add Music' button, after user has chosen some music") 48                                                                 forState: UIControlStateNormal]; 49         } 50 }