步骤如下:
1.导入AVFoundation框架,引入<AVFoundation/AVFoundation.h>
2.设置一个用于显示扫描的view
3.实例化AVCaptureSession、AVCaptureVideoPreviewLayer
@property (weak, nonatomic) IBOutlet UIView *viewPreView; //捕捉会话 @property (nonatomic, strong) AVCaptureSession *captureSession; //展示layer @property (nonatomic, strong) AVCaptureVideoPreviewLayer *videoPreviewLayer;
_captureSession = nil; [self startReading];
开始扫描
- (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为QRCode [captureMetadataOutput setMetadataObjectTypes:[NSArray arrayWithObject: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); //11.开始扫描 [_captureSession startRunning]; return YES; }
AVCaptureMetadataOutputObjectsDelegate
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection { NSString * stringValue; //判断是否有数据 if (metadataObjects != nil && [metadataObjects count] > 0) { AVMetadataMachineReadableCodeObject *metadataObj = [metadataObjects objectAtIndex:0]; stringValue = metadataObj.stringValue; } NSLog(@"%@",stringValue); [_captureSession stopRunning]; }
来源: http://www.cnblogs.com/spaceID/p/4994443.html