class XXXX: UIView {
    var url: String
    var image: UIImage? = nil
    var sadView: UIImageView = {
        let v = UIImageView()
        v.autoresizingMask = .flexibleWidth
        return v
    }()


    convenience init(frame: CGRect, url: String, callback: @escaping (_: UIImage) -> Void ) {
        self.init(frame: frame)
        self.url = url
        if let tryImage = EFQRCode.generate(
            content: url,
            watermark: UIImage(named: "XXXXXXX")?.toCGImage()
            ) {
            print("Create QRCode image success: (tryImage)")
            self.image = UIImage(cgImage: tryImage)
            self.sadView.image = self.image
        } else {
            print("Create QRCode image failed!")
        }
    }

    override init(frame: CGRect) {
        self.url = ""
        super.init(frame: frame)
        addSubview(sadView)
        constrain(sadView, self) { sadView, superView in
            sadView.centerX == superView.centerX
            sadView.width == 340
            sadView.height == 340
            sadView.centerY == superView.centerY
        }
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}