iOS cancel TouchID authentication dialog programmatically

Question

Is it possible to cancel the TouchID alert dialog programmatically after the LAContext.evaluatePolicy call? If yes: how?

Answer 1

In my case, I find out why it not working because the LAContext instance I try to invalidate() is not the same instance who I call evaluatePolicy().

So You need to make sure that all ViewControllers shared the same instance. swift 4

public class MyBiometryUtility: NSObject {
static private var sharedBiometry: MyBiometryUtility? = nil
var context: LAContext = LAContext()
@objc public static func sharedInstance() -> MyBiometryUtility{
        if let sharedBiometry = sharedBiometry {
            return sharedBiometry;
        } else{
            sharedBiometry = MyBiometryUtility()
            return sharedBiometry!
        }
    }
public func tryBiometryAuth() { ... }
public func closeBiometryAuth() {... }

In SomeViewController.swift

func buttonTapped(sender: Any){
    // show dialog.
    MyBiometryUtility.sharedInstance().tryBiometryAuth()
}
func timerCountDown(){
    // close dialog.
    if tooLong() {
        MyBiometryUtility.sharedInstance().closeBiometryAuth()
    }
}