二维码简单识别代码：

@IBOutlet weak var sourceImageView: UIImageView!

@IBAction func detectorQRCode() {

    // .1 获取需要识别的图片

    let image = sourceImageView.image

    let imageCI = CIImage(image: image!)

    // 开始识别

    // 1. 创建一个二维码探测器

    let dector = CIDetector(ofType: CIDetectorTypeQRCode, context: nil, options: [CIDetectorAccuracy: CIDetectorAccuracyHigh])

    // 2. 直接探测二维码特征

    let features = dector.featuresInImage(imageCI!)

    for feature in features {

   //        print(feature)

        let qrFeature = feature as! CIQRCodeFeature

        print(qrFeature.messageString)

        print(qrFeature.bounds)

    }

}