iOS检测耳机插入拔出

1     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(outputDeviceChanged:)name:AVAudioSessionRouteChangeNotification object:[AVAudioSession sharedInstance]];
2     [[NSNotificationCenter defaultCenter]postNotificationName:AVAudioSessionRouteChangeNotification object:self];

- (void)outputDeviceChanged:(NSNotification *)aNotification {
    AVAudioSessionRouteDescription* route = [[AVAudioSession sharedInstance] currentRoute];
    for (AVAudioSessionPortDescription* desc in [route outputs]) {
        
    if ([[desc portType] isEqualToString:AVAudioSessionPortHeadphones])
            NSLog(@"有耳机");
    else{
        NSLog(@"没有耳机");
    }
        
    }
    
            
}