卡验证

extension ViewController: AccessCheckoutCardValidationDelegate {

    // This event handler is notified when the card brand detected by the SDK has changed
    func cardBrandChanged(cardBrand: CardBrand?) {
        // This piece of code updates in the UI a card image displayed in a UIImageView next to the PAN
        // A cardBrand contains a name and an array of images objects.
        // Each image object has a URL and a type (either image/png or image/svg+xml) and represents the same brand 
        if let imageUrl = cardBrand?.images.filter({ $0.type == "image/png" }).first?.url,
            let url = URL(string: imageUrl) {

            DispatchQueue.global(qos: .userInteractive).async {
                if let data = try? Data(contentsOf: url) {
                    DispatchQueue.main.async {
                        self.imageView.image = UIImage(data: data)
                    }
                }
            }
        } else {
            // This occurs when the SDK has not been able to identify the card brand from the PAN entered by the customer
            self.imageView.image = ...
        }
    }

    // This event handler is notified when the PAN becomes valid or invalid
    func panValidChanged(isValid: Bool) {
        // You might want to change the text colour
        panTextField.textColor = isValid ? nil : UIColor.red

        if !valid {
            // You might want to disable a submit button which would normally be clicked on when all fields are valid
            submitButton.isEnabled = false
        }
    }

    // This event handler is notified when the CVC becomes valid or invalid
    func cvcValidChanged(isValid: Bool) {
        // You might want to change the text colour
        cvcTextField.textColor = isValid ? nil : UIColor.red

        if !valid {
            // You might want to disable a submit button which would normally be clicked on when all fields are valid
            submitButton.isEnabled = false
        }
    }

    // This event handler is notified when the expiry date becomes valid or invalid
    func expiryDateValidChanged(isValid: Bool) {
        // You might want to change the text colour
        expiryDateTextField.textColor = isValid ? nil : UIColor.red

        if !valid {
            // You might want to disable a submit button which would normally be clicked on when all fields are valid
            submitButton.isEnabled = false
        }
    }

    // This event handler is notified when the PAN, expiry date and CVC are all valid
    func validationSuccess() {
        // You might want to enable a submit button when all fields are valid
        submitButton.isEnabled = true
    }
}