iOS开发--二维码的扫描

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

 #import "ViewController.h"
 #import <AVFoundation/AVFoundation.h>

 @interface ViewController () <AVCaptureMetadataOutputObjectsDelegate>

 @end

 @implementation ViewController

 - (void)viewDidLoad {
     [super viewDidLoad];
 }

 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
 {
     // 1.创建捕捉会话
     AVCaptureSession *session = [[AVCaptureSession alloc] init];

     // 2.设置输入设备
     AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
     AVCaptureDeviceInput *inputDevice = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
     [session addInput:inputDevice];

     // 3.设置输入方式
     AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
     [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
     [session addOutput:output];
     [output setMetadataObjectTypes:@[AVMetadataObjectTypeQRCode]];

     // 4.添加一个显示的layer
     AVCaptureVideoPreviewLayer *layer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
     layer.frame = self.view.bounds;
     [self.view.layer addSublayer:layer];

     // 5.开始扫描
     [session startRunning];
 }

 #pragma mark - 获取扫描结果
 - (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
 {
     if (metadataObjects.count > ) {
         AVMetadataMachineReadableCodeObject *object = [metadataObjects lastObject];
         NSLog(@"%@", object.stringValue);
     }
 }

 @end