iOS自带原生二维码扫描的实现

#import

@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{

[superviewDidLoad];

 // 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;

 }];

}