iOS 红外感应

今天项目需求,当你播放音频的时候,
靠近耳朵的时候,需要把 扬声器(外放) 转为 话筒(内放)
离开耳朵的时候,需要把 话筒(内放) 转为 扬声器(外放)
就跟你打电话的时候,听筒和扬声器的转换一样!

//监听 听筒模式or扬声器模式
//监听是否靠近耳朵
#pragma mark -  开启红外感应   YES开启   NO关闭
    [[UIDevice currentDevice] setProximityMonitoringEnabled:YES]; 
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(sensorStateChange:) name:@"UIDeviceProximityStateDidChangeNotification" object:nil];

#pragma mark - 监听是否靠近耳朵
-(void)sensorStateChange:(NSNotificationCenter *)notification;
{
    AVAudioSession *session = [AVAudioSession sharedInstance];
    NSError *sessionError;
    if ([[UIDevice currentDevice] proximityState] == YES)
    {
        //靠近耳朵
        [session setCategory:AVAudioSessionCategoryPlayAndRecord error:&sessionError];
    }
    else
    {
        //远离耳朵
        [session setCategory:AVAudioSessionCategoryPlayback error:&sessionError];
    }
}