instantiateViewController problem after the app passes the face id and the touch id authentication

Question

I have added a "touch id or face id" button in my page. I have created an action for this button: btnTouchIdOrFaceIdIsPressed. Question 1: It does not open the HomePageViewController in the app screen after I click on touch id or face id button. Why?

@IBAction func btnTouchIdOrFaceIdIsPressed(_ sender: UIButton) {
    self.useBiometricAuthentication()
}

func useBiometricAuthentication () {
    let context = LAContext()
    var error : NSError?
    let reason = "some message for app user for the touch id or face id.."
    if context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) {
        context.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, localizedReason: reason) { (success, error) in
            if success {
                self.callMeAfterSuccessLoginAction()
            } else {
                //Question2: Can you write an explanation for this scope? Touch id or face is authentication is failed, right?
            }
        }
    } else {
        //Question3: Can you write an explanation for this scope? "device does not support face id or touch id", right?
    }
}

func callMeAfterSuccessLoginAction() {
    DispatchQueue.main.async {
        let oHomepageViewController = self.storyboard?.instantiateViewController(withIdentifier: "Homepage") as! HomepageViewController
        self.navigationController?.setViewControllers([oHomepageViewController], animated: true)
    }
}

Can you also reply question 2 and question 3 please?

Answer 1

Question1: It does not open the HomePageViewController in the app screen after I click on touch id or face id button. Why?

You can check if your navigationController is not nil

print(navigationController ?? "NavigationController is nil")

Question2: Can you write an explanation for this scope? Touch id or face is authentication is failed, right?

Touch ID or face ID authentication is failed

Question3: Can you write an explanation for this scope? "device does not support face id or touch id", right?

Touch ID or FaceID authentication is unavailable, may be user does not set it