我有一个奇怪的问题，当我从设备上的 XCode 构建和运行我开发的 iOS 应用程序时，它工作正常。但是，在重新启动设备并运行应用程序时，我根本听不到任何音频。如果我随后终止该应用程序并从设备重新启动它，我将再次开始获取音频。我最初认为这是一个中断处理程序问题，但我不确定了。任何帮助将不胜感激!

这是我的中断处理程序以防万一。

static void MyInterruptionListener (void *inUserData,
                                UInt32 inInterruptionState) {

printf ("Interrupted! inInterruptionState=%ld\n", inInterruptionState);
pediViewController *pediController = (__bridge pediViewController*)inUserData;
switch (inInterruptionState) {
    case kAudioSessionBeginInterruption:
        CheckError (AudioOutputUnitStop (pediController.effectState.rioUnit),
                    "Couldn't start RIO unit");
    case kAudioSessionEndInterruption:
        // TODO: doesn't work!
        CheckError(AudioSessionSetActive(true),
                   "Couldn't set audio session active");
        CheckError (AudioOutputUnitStart (pediController.effectState.rioUnit),
                    "Couldn't start RIO unit");
        break;
    default:
        break;
};

最佳答案

您应该使用音频路由更改回调来处理应用进入和退出后台，而不是中断处理程序。

无论如何，当我遇到与您自己的问题类似的问题时，这对我有用(如果我正确理解您的问题)。

举个例子

AudioSessionAddPropertyListener (
                                     kAudioSessionProperty_AudioRouteChange,
                                     audioRouteChangeListenerCallback,
                                     (__bridge void*) self
                                     );

void audioRouteChangeListenerCallback (
                                       void                      *inUserData,
                                       AudioSessionPropertyID    inPropertyID,
                                       UInt32                    inPropertyValueSize,
                                       const void                *inPropertyValue
                                       ) {

    // Ensure that this callback was invoked because of an audio route change
    if (inPropertyID != kAudioSessionProperty_AudioRouteChange) return;


    AudioEngine *audioObject = (__bridge AudioEngine *) inUserData;

    // if application sound is not playing, there's nothing to do, so return.
    if (NO == audioObject.isPlaying) {

        NSLog (@"Audio route change while application audio is stopped.");
        return;

    } else {

        CFDictionaryRef routeChangeDictionary = inPropertyValue;

        CFNumberRef routeChangeReasonRef =
        CFDictionaryGetValue (
                              routeChangeDictionary,
                              CFSTR (kAudioSession_AudioRouteChangeKey_Reason)
                              );

        SInt32 routeChangeReason;

        CFNumberGetValue (
                          routeChangeReasonRef,
                          kCFNumberSInt32Type,
                          &routeChangeReason
                          );
             if (routeChangeReason == kAudioSessionRouteChangeReason_OldDeviceUnavailable) {

            NSLog (@"Audio output device was removed; stopping audio playback.");
            NSString *MixerHostAudioObjectPlaybackStateDidChangeNotification = @"MixerHostAudioObjectPlaybackStateDidChangeNotification";
            [[NSNotificationCenter defaultCenter] postNotificationName: MixerHostAudioObjectPlaybackStateDidChangeNotification object: audioObject]; 

        } else {

            NSLog (@"A route change occurred that does not require stopping application audio.");
        }
    }
}

关于ios - 当 iPad 重新启动时，使用 RemoteIO AudioUnit 的 iOS 应用程序上没有音频，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/12355920/