识别图片二维码

点击相册按钮，打开系统相册,CIDetector可以用于人脸识别

    @IBAction func photoItem(sender: AnyObject) {
        /*
         case PhotoLibrary
         case Camera
         case SavedPhotosAlbum
         */
        //1，先查看是否可以打开相册
        if !UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.PhotoLibrary) {
            return
        }
        //2,创建UIImagePickerController
        let imagePiker = UIImagePickerController.init()
        //2.1,设置代理
        imagePiker.delegate = self
        //3,modal
        presentViewController(imagePiker, animated: true, completion: nil)  
    }

实现代理方法

// MARK - UINavigationControllerDelegate, UIImagePickerControllerDelegate代理方法
extension QRBarCodeViewController:UINavigationControllerDelegate, UIImagePickerControllerDelegate{

    func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]){
        //1,取出选中的图片
        guard let image = info[UIImagePickerControllerOriginalImage] as? UIImage else{
            return
        }
        
        
        guard let ciImage = CIImage.init(image: image)else{
            return
        }
        //2,从选中的图片中读取二维码数据
        //2.1 先创建一个探测器
        let detector = CIDetector(ofType: CIDetectorTypeQRCode, context: nil, options: [CIDetectorAccuracy:CIDetectorAccuracyLow])
        //2.2取出探测器得到的数据
        let results = detector.featuresInImage(ciImage)
        //2.3遍历探测器的数据
        for result in results
        {
            DyLog((result as! CIQRCodeFeature).messageString)
        }
        //实现了该代理方法，选中了一张图片时系统就不会自动关闭相册控制器
        picker.dismissViewControllerAnimated(true, completion: nil)
    }
}