open iphone Torch

#import "ViewController.h"

#import <AVFoundation/AVFoundation.h>

@interface ViewController ()

@property (nonatomic, assign) BOOL shouldOpen;

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.

    

    _shouldOpen = YES;

}

- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

{

    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    if (![device hasTorch]) {// 判断是否有闪光灯

        return;

    }

    

    [device lockForConfiguration:nil]; //请求独占访问硬件设备

    if (self.shouldOpen) {

        [device setTorchMode:AVCaptureTorchModeOn];

    } else {

        [device setTorchMode:AVCaptureTorchModeOff];

    }

    [device unlockForConfiguration]; // 请求解除独占访问硬件设备

    

    self.shouldOpen = !self.shouldOpen;

}

@end