Determine if an iOS device supports TouchID without setting passcode

Question

I\'m currently developing an iOS app that enables users to log in to the app using TouchID, but firstly they must set up a password inside the app first. Problem is, to show

Answer 1

I know this is a question from last year, but this solution does not make what you need? (Swift code)

if #available(iOS 8.0, *) {
    var error: NSError?
    let hasTouchID = LAContext().canEvaluatePolicy(LAPolicy.DeviceOwnerAuthenticationWithBiometrics, error: &error)

    //Show the touch id option if the device has touch id hardware feature (even if the passcode is not set or touch id is not enrolled)
    if(hasTouchID || (error?.code != LAError.TouchIDNotAvailable.rawValue)) {
        touchIDContentView.hidden = false
    } 
}

Then, when the user presses the button to log in with touch id:

@IBAction func loginWithTouchId() {
    let context = LAContext()

    var error: NSError?
    let reasonString = "Log in with Touch ID"

    if (context.canEvaluatePolicy(LAPolicy.DeviceOwnerAuthenticationWithBiometrics, error: &error)) {
        [context.evaluatePolicy(LAPolicy.DeviceOwnerAuthenticationWithBiometrics, localizedReason: reasonString, reply: { (success: Bool, evalPolicyError: NSError?) -> Void in
            //Has touch id. Treat the success boolean
        })]
    } else { 
        //Then, if the user has touch id but is not enrolled or the passcode is not set, show a alert message
        switch error!.code{

        case LAError.TouchIDNotEnrolled.rawValue:
            //Show alert message to inform that touch id is not enrolled
            break

        case LAError.PasscodeNotSet.rawValue:
            //Show alert message to inform that passcode is not set
            break

        default:
            // The LAError.TouchIDNotAvailable case.
            // Will not catch here, because if not available, the option will not visible
        }
    }
}

Hope it helps!