Proximity Sensor iOS

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    UIDevice *device = [UIDevice currentDevice];
    device.proximityMonitoringEnabled = YES;

    // Proximity Sensor Notification
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(proximityChanged:) name:@"UIDeviceProximityStateDidChangeNotification" object:device];
}

- (void)proximityChanged:(NSNotification *)notification {
    UIDevice *device = [notification object];
    if (device.proximityState == 1) {
//        [audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
        NSLog(@"Vao roi");
    } else {
        NSLog(@"Cung Vao roi");
//        [audioSession setCategory:AVAudioSessionCategoryPlayback error:nil];
    }
}

@end