Authenticating with BiometricPrompt during OnResume()

Xamarin.Android Version (eg: 6.0):

9.0

Operating System & Version (eg: Mac OSX 10.11):

Winsdows 10

Support Libraries Version (eg: 23.3.0):

AndroidX v1.0.0-rc1

Describe your Issue:

W/BiometricPromptCompat( 5060): Not launching prompt. authenticate() called after onSaveInstanceState()

Calling the Biometric Prompt during OnResume() dismisses the dialog with an error saying that the prompt cannot be launched after onSaveInstanceState() has been called.

Wrapping the call to BiometricManager in a fragment transaction with CommitAllowingStateLoss() also does not have any effect

Steps to Reproduce (with link to sample solution if possible):

Calling the Biometric Prompt during OnResume()

        public async Task<bool> Authenticate(CancellationToken cancellationToken)
        {
            var promptInfo = new BiometricPrompt.PromptInfo.Builder()
                .SetTitle("Login")
                .SetNegativeButtonText("Cancel")
                .Build();

            var activity = _activityResolver();
            var executor = Executors.NewSingleThreadExecutor();
            var handler = new BiometricsAuthenticationHandler();

            using var dialog = new BiometricPrompt((FragmentActivity) activity, executor, handler);
            await using (cancellationToken.Register(() => dialog.CancelAuthentication()))
            {
                dialog.Authenticate(promptInfo);
                return await handler.Task;
            }
        }

Include any relevant Exception Stack traces, build logs, adb logs:

W/BiometricPromptCompat( 5060): Not launching prompt. authenticate() called after onSaveInstanceState()

[moljac]

And thanks - I did have a good day. Finished Material 1.1.0 bindings (recently released by google).

[moljac]

@bradleygunn

Would you be so kind and create minimal sample, so we can add it to the samples, please?

Short readme would be even greater.

That would help other users a lot. Thanks.

And of course you could close this issue yourself.