AVAudioSession密码-锁在iOS8上停止AVAudioRecorder

Question

我有一些与背景录音有关的意外问题(特别是当屏幕被密码锁定时)。在总结中，我的AVAudioRecorder应用程序似乎正确地记录在前台、后台(切换应用程序时)和屏幕关闭时(但在激活通行证锁之前)。

如果我延迟密码锁(设置>密码>要求密码>4小时.etc)，那么录音工作时不会出现前景色/背景/应用程序切换/屏幕关闭.etc的问题，但当记录中的通行证锁启动时会损坏。

我基本上使用AVAudioRecorder代码来记录音频，并遵循了在app.plist中设置‘UIBack基power / audio’设置的指导原则，以确保背景录音，这似乎在背景中有效(即出现红色记录栏)，但当pass代码激活时，即用户按下电源按钮，并需要输入密码才能访问设备时，就会失败。

我的代码被设置为通过‘AVAudioSessionInterruptionNotification’处理音频中断，而AVAudioSession是设置为尽量减少外部事件对背景录音的影响。

测试程序

• 密码锁(iPhone 5/OS8.1>设置>密码>要求密码>5分钟后)

1. [Success-CASE-1] ‘Start Recording’ for 7mins Leave Screen On and App active/visible (i.e. not running in background after recording is started) >> Recording works and after pressing ‘Stop Recording’ audio is saved and can be played back.
2. [Success-CASE-2] ‘Start Recording’ for 7mins Leave Screen On and Switch apps (i.e. run in background with screen mostly On and Red-Recording bar displayed after recording is started) >> Recording works and after pressing ‘Stop Recording’ audio is saved and can be played back.
3. [Failure-CASE] ‘Start Recording’ for 7mins Switch Screen Off (i.e. app is running in background with devices screen off) >> After 7mins with Screen-Off, device requires passcode when screen is switched-On. Recording unexpectedly stops, becomes corrupt cannot be played back.

​

• 密码锁(iPhone 5/iOS8.1>设置>密码>要求密码> 15分钟后)

1. [Repeat-Failure-CASE with Adjusted Passlock] ‘Start Recording’ for 7mins Switch Screen Off (i.e. app is running in background with devices screen off) >> After 7mins with Screen-Off, device is switched on (no pass lock is needed this time). Recording is okay, works perfectly and can be played back.

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只有失败案例和重复失败案例之间的区别是屏幕锁密码是不需要的。

Notes

1. 使用XCode 6.1进行测试，在iPhone 4/5/6、iPad Mini 2 (iOS8.1)上测试相同的问题。
2. 代码是标准AVAudioRecorder代码，AVAudioSession设置类似于：http://www.jacopretorius.net/2013/04/record-and-playback-audio-in-ios.html

.

希望信息有所帮助，经过了大量的尝试和错误才达到这一点。

还有其他人经历过这个问题吗？因为很奇怪。

谢谢

Answer 1

当密码锁定时，您的音频文件(在沙箱中)可能受到iOS的保护；如果屏幕没有设置密码，则一切正常；

尝试以下几点：

        NSDictionary *oldAttr = [[NSFileManager defaultManager]attributesOfItemAtPath:localFilePath error:nil];
        NSMutableDictionary *newAttr = nil;
        if (oldAttr){
            newAttr = [[NSMutableDictionary alloc]initWithDictionary:oldAttr];
        }else{
            newAttr = [[NSMutableDictionary alloc]init];
        }
        [newAttr setObject:NSFileProtectionNone forKey:NSFileProtectionKey];
        [[NSFileManager defaultManager] setAttributes:newAttr
                                         ofItemAtPath:localFilePath
                                                error:nil];

或者，将证书中的数据保护设置为“关闭”。