大数据

iOS自带二维码扫描

  • 今天项目需要做一个二维码扫描,虽然有很多二维码扫描的第三方可以用,但是考虑到项目中的需要,所以我放弃了使用三方库,而采用了苹果原生的扫描。
  • 原生的二维码扫描有一个坑,那就是扫描范围的确定。只要记得扫描范围是X与Y互换位置,W与H互换位置,就没有什么问题了。
  • 下面进入正题:
    1.因为使用原生二维码扫描,所以需要加入头文件添加delegate

    #import 

    2.接着是使用到的类

    @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

    3.懒加载一个扫描动画的图片

    -(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;
    }

    4.使用前的设置,我将它设置在了viewDidLoad当中

    -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];
    }

    5.二维码扫描的代理事件

    -(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。
      }
    }

    6.添加扫描动画的事件

    - (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;
      }];
    }
  • 搞定……
  • 最后放上一张效果图

原生的扫描就是快,😄