ios - 中断后我是否需要重置 Audio Session 属性？

Question

我正在实现音频 session 中断的C侦听器。当需要中断时，我将停用音频 session 。然后，当我的应用恢复时，我将再次激活音频 session 。我已经为音频 session 设置了许多属性和类别，重新激活后是否需要重置所有设置？

提前致谢。

一些代码供引用:

初始化，设置类别:

OSStatus error = AudioSessionInitialize(NULL, NULL, interuptListenerCallBack, (__bridge void *)(self));
UInt32 category = kAudioSessionCategory_PlayAndRecord;
error = AudioSessionSetProperty(kAudioSessionProperty_AudioCategory, sizeof(category), &category);
if (error) printf("couldn't set audio category!");
//use speaker as default
UInt32 doChangeDefaultOutput = 1;
AudioSessionSetProperty(kAudioSessionProperty_OverrideCategoryDefaultToSpeaker, sizeof(doChangeDefaultOutput), &doChangeDefaultOutput);
//allow bluethoothInput 
UInt32 allowBluetoothInput = 1;
AudioSessionSetProperty(kAudioSessionProperty_OverrideCategoryEnableBluetoothInput, sizeof(allowBluetoothInput), &allowBluetoothInput);

使用interuptListenerCallBack可以使我由于中断而停用和响应音频 session ，使用

 OSStatus error = AudioSessionSetActive(false);
 if (error) printf("couldn't deactivate audio session!");

要么

  OSStatus error = AudioSessionSetActive(true);
  if (error) printf("AudioSessionSetActive (true) failed");

Answer 1

如果正确使用了音频 session 中断侦听器，则否，您不必重置属性。您只需要确保实际调用了kAudioSessionBeginInterruption和kAudioSessionEndInterruption即可。我不确定您的听众是什么样子，但是如果您正在执行以下操作:

if (inInterruptionState == kAudioSessionBeginInterruption) {
        AudioSessionSetActive(NO);
    }
    if (inInterruptionState == kAudioSessionEndInterruption) {

        AudioSessionSetActive(YES);
    }

并且遵循音频 session 的规则，那么从理论上讲，您不必重置属性。

我不知道您正在使用音频 session 做什么，但是您也可以使用以下命令暂停和恢复播放:

kAudioSessionInterruptionType_ShouldResume 

和

kAudioSessionInterruptionType_ShouldNotResume.

您可以按照文档中所述使用它们:

kAudioSessionInterruptionType_ShouldResume

Indicates that the interruption that has just ended was one for which it is appropriate to immediately resume playback; for example, an incoming phone call was rejected by the user.

Available in iOS 4.0 and later.

Declared in AudioSession.h.

kAudioSessionInterruptionType_ShouldNotResume

Indicates that the interruption that has just ended was one for which it is not appropriate to resume playback; for example, your app had been interrupted by iPod playback.

Available in iOS 4.0 and later.

Declared in AudioSession.h.

您应该阅读 docs，因为其中有很多有关暂停，恢复和处理AudioSession中断的信息。

注意:

自iOS7起，AudioSession已被弃用。请改用 AVAudioSession方法，或通过设置常量 AVAudioSessionInterruptionOptions 或 AVAudioSessionInterruptionType 来设置“暂停并继续”选项。

(自iOS 6起可用)