iOS自带原生二维码扫描的实现

#import <AVFoundation/AVFoundation.h><AVCaptureMetadataOutputObjectsDelegate>

@property (strong,nonatomic)AVCaptureDevice * device;@property (strong,nonatomic)AVCaptureDeviceInput * input;@property (strong,nonatomic)AVCaptureMetadataOutput * output;@property (strong,nonatomic)AVCaptureSession * session;@property (weak, nonatomic) IBOutlet UIView *outputView;//xib中扫描的View@property (strong,nonatomic)AVCaptureVideoPreviewLayer * preview;@property (strong, nonatomic) NSTimer * timer;//为了做扫描动画的定时器@property (strong, nonatomic) UIImageView * lineImage;//扫描动画的横线

-(UIImageView *)lineImage{ if (!_lineImage) {  CGFloat outputW = self.outputView.frame.size.width;  _lineImage = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0,outputW, 2)];  _lineImage.image = [UIImage imageNamed:@"ray"]; } return _lineImage;}

-viewDidLoad{[super viewDidLoad]; // Device _device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; // Input _input = [AVCaptureDeviceInput deviceInputWithDevice:self.device error:nil]; // Output _output = [[AVCaptureMetadataOutput alloc]init]; [_output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()]; // Session _session = [[AVCaptureSession alloc]init]; [_session setSessionPreset:AVCaptureSessionPresetHigh]; //连接输入和输出 if ([_session canAddInput:self.input]) {  [_session addInput:self.input]; } if ([_session canAddOutput:self.output]) {  [_session addOutput:self.output]; }//设置条码类型 _output.metadataObjectTypes =@[AVMetadataObjectTypeQRCode]; //设置条码位置 CGFloat X = (ScreenW/2-100)/ScreenW; CGFloat Y = (ScreenH/2-100)/ScreenH; CGFloat W = 200/ScreenW; CGFloat H = 200/ScreenH; //设置扫描范围（注意，X与Y交互，W与H交换） [_output setRectOfInterest:CGRectMake(Y, X, H, W)];//添加扫描画面 _preview =[AVCaptureVideoPreviewLayer layerWithSession:_session]; _preview.videoGravity =AVLayerVideoGravityResizeAspectFill; _preview.frame = CGRectMake(0, 0, ScreenW, ScreenH);//self.view.layer.bounds; [self.view.layer insertSublayer:_preview atIndex:0]; //开始扫描 [_session startRunning];//添加扫描动画定时器[self.outputView addSubview:self.lineImage]; // Do any additional setup after loading the view from its nib. _timer = [NSTimer scheduledTimerWithTimeInterval:2.5f           target:self           selector:@selector(lineAction)           userInfo:nil           repeats:YES];}

-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection{ NSString *stringValue; if ([metadataObjects count] >0){  //停止扫描  [_session stopRunning];  AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjects objectAtIndex:0];  stringValue = metadataObject.stringValue;//stringValue是扫描拿到的内容，更具内容进行后续工作。 }}

- (void)lineAction{ CGFloat outputW = self.outputView.frame.size.width; CGFloat outputH = self.outputView.frame.size.height; [UIView animateWithDuration:2.4f animations:^{  CGRect frame = CGRectMake(0, outputH, outputW, 2);  self.lineImage.frame = frame; } completion:^(BOOL finished) {  CGRect frame = CGRectMake(0, 0, outputW, 2);  self.lineImage.frame = frame; }];}