1.导入AVFoundatin.framework。
2.新建一个viewController，命名为QRScanViewController，用于扫描的界面。
h文件如下，设置代理。
#import <UIKit/UIKit.h> #import <AVFoundation/AVFoundation.h> @protocol QRScanDelegate <NSObject> -(void)ReadScan:(NSString *)codetext; @end @interface QRScanViewController : UIViewController //<AVCaptureMetadataOutputObjectsDelegate> { id<QRScanDelegate> delegate; } @property (nonatomic,retain) id <QRScanDelegate> delegate; @property (strong,nonatomic) UIView *boxView; @property (strong,nonatomic) CALayer *scanLayer; -(BOOL) startReading; -(void) stopReading; @property (nonatomic,strong) AVCaptureSession *captureSession; @property (nonatomic,strong) AVCaptureVideoPreviewLayer *videoPreviewLayer; @property (strong, nonatomic) UIView *viewPreview; @end
m文件内容如下
#import "QRScanViewController.h" @interface QRScanViewController () @end @implementation QRScanViewController - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view. self.captureSession = nil; // 设置扫描界面 self.viewPreview = [[UIView alloc] initWithFrame:CGRectMake(self.view.frame.origin.x,self.view.frame.origin.y,self.view.frame.size.width,self.view.frame.size.height)]; [self.view addSubview:self.viewPreview]; //开始扫描 [self startReading]; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } -(BOOL) startReading { NSError *error; //1.初始化捕捉设备（AVCaptureDevice），类型为AVMediaTypeVideo AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; //2.用captureDevice创建输入流 AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:&error]; if (!input) { NSLog(@"%@", [error localizedDescription]); return NO; } //3.创建媒体数据输出流 AVCaptureMetadataOutput *captureMetadataOutput = [[AVCaptureMetadataOutput alloc] init]; //4.实例化捕捉会话 _captureSession = [[AVCaptureSession alloc] init]; //4.1.将输入流添加到会话 [_captureSession addInput:input]; //4.2.将媒体输出流添加到会话中 [_captureSession addOutput:captureMetadataOutput]; //5.创建串行队列，并加媒体输出流添加到队列当中 dispatch_queue_t dispatchQueue; dispatchQueue = dispatch_queue_create("myQueue", NULL); //5.1.设置代理 [captureMetadataOutput setMetadataObjectsDelegate:self queue:dispatchQueue]; //5.2.设置输出媒体数据类型，此处设置了多个条形码及二维码的类型 [captureMetadataOutput setMetadataObjectTypes:@[AVMetadataObjectTypeEAN13Code,AVMetadataObjectTypeEAN8Code,AVMetadataObjectTypeCode128Code,AVMetadataObjectTypeCode39Code,AVMetadataObjectTypeQRCode]]; //6.实例化预览图层 _videoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:_captureSession]; //7.设置预览图层填充方式 [_videoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill]; //8.设置图层的frame [_videoPreviewLayer setFrame:_viewPreview.layer.bounds]; //9.将图层添加到预览view的图层上 [_viewPreview.layer addSublayer:_videoPreviewLayer]; //10.设置扫描范围 captureMetadataOutput.rectOfInterest = CGRectMake(0.2f, 0.2f, 0.8f, 0.8f); //10.1.扫描框 _boxView = [[UIView alloc] initWithFrame:CGRectMake(_viewPreview.bounds.size.width * 0.2f, _viewPreview.bounds.size.height * 0.2f, _viewPreview.bounds.size.width - _viewPreview.bounds.size.width * 0.4f, _viewPreview.bounds.size.height - _viewPreview.bounds.size.height * 0.4f)]; _boxView.layer.borderColor = [UIColor greenColor].CGColor; _boxView.layer.borderWidth = 1.0f; [_viewPreview addSubview:_boxView];//10.开始扫描 [_captureSession startRunning]; return YES; } #pragma mark - AVCaptureMetadataOutputObjectsDelegate - (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection { //判断是否有数据 if (metadataObjects != nil && [metadataObjects count] > 0) { AVMetadataMachineReadableCodeObject *metadataObj = [metadataObjects objectAtIndex:0]; //判断回传的数据类型 if ([[metadataObj type] isEqualToString:AVMetadataObjectTypeQRCode]|| [[metadataObj type] isEqualToString:AVMetadataObjectTypeEAN13Code]|| [[metadataObj type] isEqualToString:AVMetadataObjectTypeEAN8Code]|| [[metadataObj type] isEqualToString:AVMetadataObjectTypeCode128Code]|| [[metadataObj type] isEqualToString:AVMetadataObjectTypeCode39Code] ) { NSString *code = [metadataObj stringValue]; [self performSelectorOnMainThread:@selector(stopReading) withObject:nil waitUntilDone:NO]; NSLog(@"send:%@",code);
//此地方是为了保证ui运行在主线程中。 dispatch_async(dispatch_get_main_queue(), ^{ [self.delegate ReadScan:code]; [self dismissViewControllerAnimated:YES completion:nil]; }); } } } -(void) stopReading { [self.captureSession stopRunning]; self.captureSession = nil; //[self.scanLayer removeFromSuperlayer]; [self.videoPreviewLayer removeFromSuperlayer]; }
3.新建主界面，添加按钮和标签
使用代理
@interface ViewController : UIViewController <QRScanDelegate>
启动扫描
QRScanViewController *scan = [[QRScanViewController alloc] init]; scan.delegate = self; [self presentModalViewController:scan animated:NO];
实现代理方法
-(void)ReadScan:(NSString *)codetext { self.txtTxm.text = codetext; NSLog(@"recvcode:%@",codetext); }
总结：
第一是要注意条形码的类型。
第二是保证让ui运行在主线程中，不然会有延时。