iOS5，iOS6爲什麼AVAudioPlayer播放在屏幕鎖定時停止？

我一直在爲幾個iOS應用程序使用AVAudioPlayer，它們都在屏幕鎖定之前成功回放，直到我的iPad2上的iOS6（或iOS5），現在它們停止。這是我如何設置它，它用來做工精細：iOS5，iOS6爲什麼AVAudioPlayer播放在屏幕鎖定時停止？

// Registers this class as the delegate of the audio session. 
    [[AVAudioSession sharedInstance] setDelegate: self]; 

    // Use this code instead to allow the app sound to continue to play when the screen is locked. 
    [[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryPlayback error: nil]; 

    UInt32 doSetProperty = 0; 
    AudioSessionSetProperty (kAudioSessionProperty_OverrideCategoryMixWithOthers, 
          sizeof (doSetProperty), 
          &doSetProperty 
          ); 

    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents]; 

    // Registers the audio route change listener callback function 
    AudioSessionAddPropertyListener (
            kAudioSessionProperty_AudioRouteChange, 
            audioRouteChangeListenerCallback, 
            (__bridge void *)self 
            ); 

// Activates the audio session. 

    NSError *activationError = nil; 
    [[AVAudioSession sharedInstance] setActive: YES error: &activationError]; 

    // Instantiates the AVAudioPlayer object, initializing it with the sound 

    AVAudioPlayer *newPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL: medURL error: nil]; 
    self.appSoundPlayer = newPlayer; 

    // "Preparing to play" attaches to the audio hardware and ensures that playback 
    //  starts quickly when the user taps Play 
    [appSoundPlayer prepareToPlay]; 
    [appSoundPlayer setVolume: 0.5]; 
    [appSoundPlayer setDelegate: self];

注意，我設置的類別AVAudioSessionCategoryPlayback這是以前推薦的修補程序。這不起作用，因爲我已升級到iOS6 - 也不適用於iOS5，因爲它變成了！

更新：我發現，似乎是基於對這個職位的工作答案：AVAudioPlayer stops playing on screen lock even though the category is AVAudioSessionCategoryPlayback

基本上我走進了目標的信息頁，並增加了新的密鑰「所需的背景模式」，這個我加字符串類型值「應用程序播放音頻」。現在，它可以在完全關閉屏幕之前完成整個軌道。

來源

2012-12-16 Alan Moore