iOS - 无法播放音频文件

Question

我正在尝试在 iPhone 上播放 mp3 音频文件，执行以下代码:

    NSURL *audioURL = [NSURL URLWithString:[NSString stringWithFormat:@"%@%@/%@.mp3", FONYK_FILES_URL, [self.voicenote valueForKeyPath:@"Fonyker.fonykid"], [self.voicenote valueForKeyPath:@"Voicenote.vnid"]]];
    NSData *audioData = [NSData dataWithContentsOfURL:audioURL];
    NSString *filePath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
                                                               NSUserDomainMask, YES) objectAtIndex:0] 
                          stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.mp3", [self.voicenote valueForKeyPath:@"Voicenote.vnid"]]];
    [audioData writeToFile:filePath atomically:YES];
    NSError *error = nil;
    AVAudioPlayer *audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:filePath] error:&error];
    [audioPlayer play];

当它到达 AVAudioPlayer 实例化时，它在调试器中输出:

2012-03-15 17:08:51.531 Fonyk[13004:10703] Error loading /System/Library/Extensions/AudioIPCDriver.kext/Contents/Resources/AudioIPCPlugIn.bundle/Contents/MacOS/AudioIPCPlugIn:  dlopen(/System/Library/Extensions/AudioIPCDriver.kext/Contents/Resources/AudioIPCPlugIn.bundle/Contents/MacOS/AudioIPCPlugIn, 262): Symbol not found: ___CFObjCIsCollectable
  Referenced from: /System/Library/Frameworks/Security.framework/Versions/A/Security
  Expected in: /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation
 in /System/Library/Frameworks/Security.framework/Versions/A/Security
2012-03-15 17:08:51.544 Fonyk[13004:10703] Error loading /System/Library/Extensions/AudioIPCDriver.kext/Contents/Resources/AudioIPCPlugIn.bundle/Contents/MacOS/AudioIPCPlugIn:  dlopen(/System/Library/Extensions/AudioIPCDriver.kext/Contents/Resources/AudioIPCPlugIn.bundle/Contents/MacOS/AudioIPCPlugIn, 262): Symbol not found: ___CFObjCIsCollectable
  Referenced from: /System/Library/Frameworks/Security.framework/Versions/A/Security
  Expected in: /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation
 in /System/Library/Frameworks/Security.framework/Versions/A/Security

找不到任何相关内容，知道发生了什么吗？

Answer 1

尝试创建 AVURLAsset 并按照 AV Foundation Programming Guide 中的描述异步加载它的轨道.在完成 block 中，您可以创建一个 AVPlayerItem 并将其传递给播放器。

根据 AV Foundation Release Notes for iOS 5 ，从 iOS 5 开始，如果轨道尚未加载，播放器应加载轨道。然而，根据我的经验，这是行不通的。手动加载它们是可行的，所以这就是我所做的。