I am trying to write a tweak in Theos for an iOS app, to play a silent wav in background for more background life. There might be incoming calls interrupt the sound playing, so I wrote the following notification handling. It should work, the audio player can be restarted, but playing the sound for a very short time, about 0.3s. And then the player will be deactived and stopped.

我正试图在Theos中为iOS应用程序写一个调整，在背景中播放无声的wav，以获得更多的背景生活。可能会有来电中断声音播放，所以我写了下面的通知处理。它应该可以工作，音频播放器可以重新启动，但播放声音的时间很短，大约0.3秒。然后播放器将被停用。

I've already tried to insert many many hook logs, still not find any clue. Anyone help me? I am very appreciated. I am new to developing iOS tweaks. Are there some tools to debug this issue?

我已经试着插入了很多钩子日志，但仍然没有找到任何线索。有人帮我吗？我非常感激。我是开发iOS调整的新手。是否有一些工具可以调试此问题？

// Register interruption handler
[[NSNotificationCenter defaultCenter]  addObserver:self  
                                          selector:@selector(audioSessionInterruption:)  
                                          name:AVAudioSessionInterruptionNotification  
                                          object:nil];

- (void)audioSessionInterruption:(NSNotification *)notification{
   NSNumber *interruptionType = [[notification userInfo] objectForKey:AVAudioSessionInterruptionTypeKey];
   NSNumber *interruptionOption = [[notification userInfo] objectForKey:AVAudioSessionInterruptionOptionKey];

   switch (interruptionType.unsignedIntegerValue) {
      case AVAudioSessionInterruptionTypeBegan:{
         NSLog(@"AVAudioSessionInterruptionTypeBegan");
      } break;
      case AVAudioSessionInterruptionTypeEnded:{
         if (interruptionOption.unsignedIntegerValue == AVAudioSessionInterruptionOptionShouldResume) {
               // Here should continue playback. Active audio session and play
               // Unfortunately, the audio player playing less one second, and be deactived by something
               NSLog(@"AVAudioSessionInterruptionTypeEnded");
               [[AVAudioSession sharedInstance] setActive:YES error:nil];
               [self.audioPlayer play];
         }
      } break;
      default:
         break;
   }
}

Check the logs, I found that the AudioSession was successfully activated but was promptly deactivated.

查看日志，我发现AudioSession已成功激活，但很快被停用。

CAReportingClient.mm:508   message {API = "[AVAudioSession etActive:activate]";    ElapsedTime = "6.517041";}: (176093659500)
CAReportingClient.mm:508   message {API = "-[AVAudioSession ategory]";    ElapsedTime = "0.158375";}: (176093659500)
CAReportingClient.mm:508   message {API = "-[AVAudioSession privateSetCategoryWithOptions:modes:routeSharingPolicy:options:]";    ElapsedTime = "5.618958";}: (176093659500)
AVAudioSession_iOS.mm:1271  Deactivating an audio session that has running I/O. All I/O should be stopped or paused prior to deactivating the audio session.
CAReportingClient.mm:508   message {API = "[AVAudioSession setActive:deactivate]";    ElapsedTime = "656.548541";}: (176093659500)

I want to find out which process deactive the audio player, and avoid it or write a hook to handle it. May be there is another notification interruption handler in this IOS app?

我想知道是哪个进程使音频播放器失效，并避免它或写一个钩子来处理它。可能在这个IOS应用程序中还有另一个通知中断处理程序？

Finally I found the solution. Something changed audio session category options just after interruption being ended. The workaround is make a delay 3 seconds and change it back

最后我找到了解决办法。中断刚结束，音频会话类别选项就发生了变化。解决方法是延迟3秒并将其改回

- (void)audioSessionInterruption:(NSNotification *)notification{
   NSNumber *interruptionType = [[notification userInfo] objectForKey:AVAudioSessionInterruptionTypeKey];
   NSNumber *interruptionOption = [[notification userInfo] objectForKey:AVAudioSessionInterruptionOptionKey];

   switch (interruptionType.unsignedIntegerValue) {
      case AVAudioSessionInterruptionTypeBegan:{
         // • Audio has stopped, already inactive
         // • Change state of UI, etc., to reflect non-playing state
         NSLog(@"AVAudioSession interruption type began");
      } break;
      case AVAudioSessionInterruptionTypeEnded:{
         // • Make session active
         // • Update user interface
         // • AVAudioSessionInterruptionOptionShouldResume option
         if (interruptionOption.unsignedIntegerValue == AVAudioSessionInterruptionOptionShouldResume) {
               // Here you should continue playback.
               NSLog(@"AVAudioSession interruption type ended");
               // Something changed audio session category options, here delay 3 seconds and change it back
               dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 3 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
                  NSLog(@"Resume silence audio play from interruption");
                  [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback 
                                                   withOptions:AVAudioSessionCategoryOptionMixWithOthers error:nil];
                  [[AVAudioSession sharedInstance] setActive:YES error:nil];
                  [self.audioPlayer play];
               });
         }
      } break;
      default:
         break;
   }
}