利用AVFoundation框架比第三方框架识别二维码更快速,并且第三方框架不支持64位,本篇文章使用AVFoundation框架来完成二维码读取

二维码的读取

1.创建一个捕捉会话

let session = AVCaptureSession()

2.设置输入设备

let device = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
guard let deviceInput = try? AVCaptureDeviceInput(device: device) else {
            print("没有获取到输入设备")
            return
        }
session.addInput(deviceInput)

3.设置输出设备和代理

let output = AVCaptureMetadataOutput()
output.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())
session.addOutput(output)
output.metadataObjectTypes = output.availableMetadataObjectTypes

4.设置扫描范围为扫描框内,注意,设置范围的x,y轴是于iOS的x,y轴相反的

let rect = UIScreen.mainScreen().bounds
// containerView是扫描框控件
let containerRect = containerView.frame
output.rectOfInterest = CGRect(x: containerRect.origin.y / rect.size.height , y: containerRect.origin.x / rect.size.width, width: containerRect.size.height / rect.size.height, height: containerRect.size.width / rect.size.width)

5.添加预览图层并开始扫描

let previewLayer = AVCaptureVideoPreviewLayer(session: session)
previewLayer.frame = UIScreen.mainScreen().bounds
view.layer.insertSublayer(previewLayer, atIndex: 0)
self.previewLayer = previewLayer
       
session.startRunning()

6.在代理方法中获得扫描的数据并设置将获得的数据显示出来

func captureOutput(captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [AnyObject]!, fromConnection connection: AVCaptureConnection!)

从相册读取二维码

1.创建照片源

        if !UIImagePickerController.isSourceTypeAvailable(.PhotoLibrary) {
            print("照片库不可用")
            return
        }
        
        // 创建选择照片的控制器
        let ipc = UIImagePickerController()
        
        // 设置照片源
        ipc.sourceType = .PhotoLibrary
        
        // 设置代理
        ipc.delegate = self
        
        // 弹出控制器
        presentViewController(ipc, animated: true, completion: nil)

2.在代理方法中拿到照片并读取

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
        // 拿到图片
        guard let image = info[UIImagePickerControllerOriginalImage] as? UIImage else {
            print("没有获取到照片")
            return
        }

        // 创建扫描器
        let detector = CIDetector(ofType: CIDetectorTypeQRCode, context: nil, options: nil)
        
        // 扫描结果
        guard let ciImage = CIImage(image: image) else {
            print("转ciImage失败")
            return
        }

        let features = detector.featuresInImage(ciImage)

        // 遍历扫描结果
        for f in features {
            guard let feature = f as? CIQRCodeFeature else {
                continue
            }
            
            print(feature.messageString)
        }

    }

生成二维码,并且在二维码中心画上头像

override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建滤镜
        let filter = CIFilter(name: "CIQRCodeGenerator")
        
        // 恢复默认设置
        filter?.setDefaults()
        
        // 设置数据
        let qrcodeInfo = "http://www.jianshu.com/users/d4396e83f3b4/latest_articles"
        guard let qrcodeInfoData = qrcodeInfo.dataUsingEncoding(NSUTF8StringEncoding) else {
            return
        }
        filter?.setValue(qrcodeInfoData, forKeyPath: "inputMessage")
        
        // 获取生成的图片
        guard let outputImage = filter?.outputImage else {
            return
        }
        
        // 设置图片
        let image = scaleImage(outputImage)
        
        // 在二维码中画上头像
        qrcodeView.image = drawIconView(image, iconName: "111")
    }
    
    private func drawIconView(image : UIImage, iconName : String) -> UIImage {
        // 开启图片上下文
        UIGraphicsBeginImageContext(image.size)
        
        // 将图片画到上下文中
        image.drawInRect(CGRect(origin: CGPointZero, size: image.size))
        
        // 根据图标名称生成图片,并且将图片画到上下文中
        let iconImage = UIImage(named: iconName)
        let width : CGFloat = 60
        let height : CGFloat = 60
        let x = (image.size.width - width) * 0.5
        let y = (image.size.height - height) * 0.5
        iconImage?.drawInRect(CGRect(x: x, y: y, width: width, height: height))
        
        // 获取图片
        let drawImage = UIGraphicsGetImageFromCurrentImageContext()
        
        // 关闭上下文
        UIGraphicsEndImageContext()
        
        return drawImage
    }
    // 放大生成的二维码
    private func scaleImage(ciImage : CIImage) -> UIImage {
        // 创建放大的系数
        let tranform = CGAffineTransformMakeScale(10, 10)
        
        // 根据放大系数放大的图片
        let newImage = ciImage.imageByApplyingTransform(tranform)
        
        // 返回生成好的图片
        return UIImage(CIImage: newImage)
    }