如何在iOS设备上控制闪光灯的开启与关闭功能

//
//  ViewController.m
//  Flash
//
//  Created by fe on 2017/1/3.
//  Copyright © 2017年 fe. All rights reserved.
//

#import "ViewController.h"
#import //调用闪光灯需要导入该框架
@interface ViewController ()

- (IBAction)openFlash:(UIButton *)sender;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}


- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


- (IBAction)openFlash:(UIButton *)sender {
    
    sender.selected = !sender.selected;
    if (sender.isSelected == YES) { //打开闪光灯
        AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
        NSError *error = nil;
        
        if ([captureDevice hasTorch]) {
            BOOL locked = [captureDevice lockForConfiguration:&error];
            if (locked) {
                captureDevice.torchMode = AVCaptureTorchModeOn;
                [captureDevice unlockForConfiguration];
            }
        }
    }else{//关闭闪光灯
        AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
        if ([device hasTorch]) {
            [device lockForConfiguration:nil];
            [device setTorchMode: AVCaptureTorchModeOff];
            [device unlockForConfiguration];
        }
    }
   

    
}
- (IBAction)closeFlash:(UIButton *)sender {
    
}

@end