一.需要包含头文件

#import <AVFoundation/AVFoundation.h>

二.通过设置<AVCaptureMetadataOutputObjectsDelegate>代理可以监听扫描到的二维码中的信息

三.具体代码

1 #import "ViewController.h" 2 #import 
     
       3  4 @interface ViewController () 
      
        5  6 @end 7  8 @implementation ViewController 9 10 - (void)viewDidLoad {11     [super viewDidLoad];12 }13 14 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event15 {16     // 1.创建捕捉会话17     AVCaptureSession *session = [[AVCaptureSession alloc] init];18     19     // 2.设置输入设备20     AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];21     AVCaptureDeviceInput *inputDevice = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];22     [session addInput:inputDevice];23     24     // 3.设置输入方式25     AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];26     [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];27     [session addOutput:output];28     [output setMetadataObjectTypes:@[AVMetadataObjectTypeQRCode]];29     30     // 4.添加一个显示的layer31     AVCaptureVideoPreviewLayer *layer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];32     layer.frame = self.view.bounds;33     [self.view.layer addSublayer:layer];34     35     // 5.开始扫描36     [session startRunning];37 }38 39 #pragma mark - 获取扫描结果40 - (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection41 {42     if (metadataObjects.count > 0) {43         AVMetadataMachineReadableCodeObject *object = [metadataObjects lastObject];44         NSLog(@"%@", object.stringValue);45     }46 }47 48 @end