BiometricPrompt

Kotlin |Java

open class BiometricPrompt

kotlin.Any
↳	androidx.biometric.BiometricPrompt

A class that manages a system-provided biometric prompt. On devices running Android 9.0 (API 28) and above, this will show a system-provided authentication prompt, using one of the device's supported biometric modalities (fingerprint, iris, face, etc). Prior to Android 9.0, this will instead show a custom fingerprint authentication dialog. The prompt will persist across configuration changes unless explicitly canceled. For security reasons, the prompt will be dismissed when the client application is no longer in the foreground.

To persist authentication across configuration changes, developers should (re)create the prompt every time the activity/fragment is created. Instantiating the prompt with a new callback early in the fragment/activity lifecycle (e.g. in onCreate()) will allow the ongoing authentication session's callbacks to be received by the new fragment/activity instance. Note that cancelAuthentication() should not be called, and authenticate() does not need to be invoked during activity/fragment creation.

Summary

Nested classes
abstract	AuthenticationCallback A collection of methods that may be invoked by BiometricPrompt during authentication.
open	AuthenticationResult A container for data passed to AuthenticationCallback#onAuthenticationSucceeded( * AuthenticationResult) when the user has successfully authenticated.
open	CryptoObject A wrapper class for the crypto objects supported by BiometricPrompt.
open	PromptInfo A set of configurable options for how the BiometricPrompt should appear and behave.

Constants
static Int	AUTHENTICATION_RESULT_TYPE_BIOMETRIC Authentication type reported by AuthenticationResult when the user authenticated by presenting some form of biometric (e.g. fingerprint or face).
static Int	AUTHENTICATION_RESULT_TYPE_DEVICE_CREDENTIAL Authentication type reported by AuthenticationResult when the user authenticated by entering their device PIN, pattern, or password.
static Int	AUTHENTICATION_RESULT_TYPE_UNKNOWN Authentication type reported by AuthenticationResult when the user authenticated via an unknown method.
static Int	ERROR_CANCELED The operation was canceled because the biometric sensor is unavailable.
static Int	ERROR_HW_NOT_PRESENT The device does not have the required authentication hardware.
static Int	ERROR_HW_UNAVAILABLE The hardware is unavailable.
static Int	ERROR_LOCKOUT The operation was canceled because the API is locked out due to too many attempts.
static Int	ERROR_LOCKOUT_PERMANENT The operation was canceled because ERROR_LOCKOUT occurred too many times.
static Int	ERROR_NEGATIVE_BUTTON The user pressed the negative button.
static Int	ERROR_NO_BIOMETRICS The user does not have any biometrics enrolled.
static Int	ERROR_NO_DEVICE_CREDENTIAL The device does not have pin, pattern, or password set up.
static Int	ERROR_NO_SPACE The operation can't be completed because there is not enough device storage remaining.
static Int	ERROR_SECURITY_UPDATE_REQUIRED A security vulnerability has been discovered with one or more hardware sensors.
static Int	ERROR_TIMEOUT The current operation has been running too long and has timed out.
static Int	ERROR_UNABLE_TO_PROCESS The sensor was unable to process the current image.
static Int	ERROR_USER_CANCELED The user canceled the operation.
static Int	ERROR_VENDOR The operation failed due to a vendor-specific error.

Public constructors
<init>(@NonNull activity: FragmentActivity, @NonNull callback: BiometricPrompt.AuthenticationCallback) Constructs a BiometricPrompt, which can be used to prompt the user to authenticate with a biometric such as fingerprint or face.
<init>(@NonNull fragment: Fragment, @NonNull callback: BiometricPrompt.AuthenticationCallback) Constructs a BiometricPrompt, which can be used to prompt the user to authenticate with a biometric such as fingerprint or face.
<init>(@NonNull activity: FragmentActivity, @NonNull executor: Executor, @NonNull callback: BiometricPrompt.AuthenticationCallback) Constructs a BiometricPrompt, which can be used to prompt the user to authenticate with a biometric such as fingerprint or face.
<init>(@NonNull fragment: Fragment, @NonNull executor: Executor, @NonNull callback: BiometricPrompt.AuthenticationCallback) Constructs a BiometricPrompt, which can be used to prompt the user to authenticate with a biometric such as fingerprint or face.

Public methods
open Unit	authenticate(@NonNull info: BiometricPrompt.PromptInfo, @NonNull crypto: BiometricPrompt.CryptoObject) Shows the biometric prompt to the user.
open Unit	authenticate(@NonNull info: BiometricPrompt.PromptInfo) Shows the biometric prompt to the user.
open Unit