Added in API level 28

Summary: Ctors | Methods | Inherited Methods

BiometricPrompt.Builder

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Kotlin |Java

public static class BiometricPrompt.Builder
extends Object

java.lang.Object
↳	android.hardware.biometrics.BiometricPrompt.Builder

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A builder that collects arguments to be shown on the system-provided biometric dialog.

Summary

Public constructors
Builder(Context context) Creates a builder for a BiometricPrompt dialog.

Public methods
BiometricPrompt	build() Creates a BiometricPrompt.
BiometricPrompt.Builder	setAllowedAuthenticators(int authenticators) Optional: Specifies the type(s) of authenticators that may be invoked by BiometricPrompt to authenticate the user.
BiometricPrompt.Builder	setConfirmationRequired(boolean requireConfirmation) Optional: Sets a hint to the system for whether to require user confirmation after authentication.
BiometricPrompt.Builder	setContentView(PromptContentView view) Optional: Sets application customized content view that will be shown on the prompt.
BiometricPrompt.Builder	setDescription(CharSequence description) Optional: Sets a description that will be shown on the prompt.
BiometricPrompt.Builder	setDeviceCredentialAllowed(boolean allowed) This method was deprecated in API level 30. Replaced by setAllowedAuthenticators(int).
BiometricPrompt.Builder	setLogoBitmap(Bitmap logoBitmap) Optional: Sets the bitmap drawable of the logo that will be shown on the prompt.
BiometricPrompt.Builder	setLogoDescription(String logoDescription) Optional: Sets logo description text that will be shown on the prompt.
BiometricPrompt.Builder	setLogoRes(int logoRes) Optional: Sets the drawable resource of the logo that will be shown on the prompt.
BiometricPrompt.Builder	setNegativeButton(CharSequence text, Executor executor, DialogInterface.OnClickListener listener) Required: Sets the text, executor, and click listener for the negative button on the prompt.
BiometricPrompt.Builder	setSubtitle(CharSequence subtitle) Optional: Sets a subtitle that will be shown on the prompt.
BiometricPrompt.Builder	setTitle(CharSequence title) Required: Sets the title that will be shown on the prompt.

Inherited methods

From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait(long timeoutMillis, int nanos) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait(long timeoutMillis) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait() Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Public constructors

Builder

Added in API level 28

public Builder (Context context)

Creates a builder for a BiometricPrompt dialog.

Parameters
context	Context: The Context that will be used to build the prompt.

Public methods

build

Added in API level 28

public BiometricPrompt build ()

Creates a BiometricPrompt.

Returns
BiometricPrompt	An instance of BiometricPrompt. This value cannot be null.

Throws
IllegalArgumentException	If any required fields are unset, or if given any invalid combination of field values.

setAllowedAuthenticators

Added in API level 30

public BiometricPrompt.Builder setAllowedAuthenticators (int authenticators)

Optional: Specifies the type(s) of authenticators that may be invoked by BiometricPrompt to authenticate the user. Available authenticator types are defined in Authenticators and can be combined via bitwise OR. Defaults to:

• Authenticators.BIOMETRIC_WEAK for non-crypto authentication, or
• Authenticators.BIOMETRIC_STRONG for crypto-based authentication.

If this method is used and no authenticator of any of the specified types is available at the time BiometricPrompt#authenticate(...) is called, authentication will be canceled and AuthenticationCallback.onAuthenticationError(int, CharSequence) will be invoked with an appropriate error code.

This method should be preferred over setDeviceCredentialAllowed(boolean) and overrides the latter if both are used. Using this method to enable device credential authentication (with Authenticators.DEVICE_CREDENTIAL) will replace the negative button on the prompt, making it an error to also call setNegativeButton(java.lang.CharSequence, java.util.concurrent.Executor, android.content.DialogInterface.OnClickListener).

If unlocking cryptographic operation(s), it is the application's responsibility to request authentication with the proper set of authenticators (e.g. match the authenticators specified during key generation).

Parameters

authenticators

int: A bit field representing all valid authenticator types that may be invoked by the prompt. Value is either 0 or a combination of BiometricManager.Authenticators.BIOMETRIC_STRONG, BiometricManager.Authenticators.BIOMETRIC_WEAK, android.hardware.biometrics.BiometricManager.Authenticators.BIOMETRIC_CONVENIENCE, BiometricManager.Authenticators.DEVICE_CREDENTIAL, and android.hardware.biometrics.BiometricManager.Authenticators.IDENTITY_CHECK

Returns
BiometricPrompt.Builder	This builder. This value cannot be null.

See also:

• KeyGenParameterSpec.Builder
• KeyProperties.AUTH_BIOMETRIC_STRONG
• KeyProperties.AUTH_DEVICE_CREDENTIAL

setConfirmationRequired

Added in API level 29

public BiometricPrompt.Builder setConfirmationRequired (boolean requireConfirmation)

Optional: Sets a hint to the system for whether to require user confirmation after authentication. For example, implicit modalities like face and iris are passive, meaning they don't require an explicit user action to complete authentication. If set to true, these modalities should require the user to take some action (e.g. press a button) before AuthenticationCallback.onAuthenticationSucceeded(AuthenticationResult) is called. Defaults to true.

A typical use case for not requiring confirmation would be for low-risk transactions, such as re-authenticating a recently authenticated application. A typical use case for requiring confirmation would be for authorizing a purchase.

Note that this just passes a hint to the system, which the system may then ignore. For example, a value of false may be ignored if the user has disabled implicit authentication in Settings, or if it does not apply to a particular modality (e.g. fingerprint).

Parameters
requireConfirmation	boolean: true if explicit user confirmation should be required, or false otherwise.

Returns
BiometricPrompt.Builder	This builder. This value cannot be null.

setContentView

Added in API level 35

public BiometricPrompt.Builder setContentView (PromptContentView view)

Optional: Sets application customized content view that will be shown on the prompt.

Note that the description set by Builder.setDescription(CharSequence) will be overridden by Builder.setContentView(PromptContentView). The view provided to Builder.setContentView(PromptContentView) will be used if both methods are called.

Parameters
view	PromptContentView: The customized view information. This value cannot be null.

Returns
BiometricPrompt.Builder	This builder. This value cannot be null.

setDescription

Added in API level 28

public BiometricPrompt.Builder setDescription (CharSequence description)

Optional: Sets a description that will be shown on the prompt.

Note that the description set by Builder.setDescription(CharSequence) will be overridden by Builder.setContentView(PromptContentView). The view provided to Builder.setContentView(PromptContentView) will be used if both methods are called.

Parameters
description	CharSequence: The description to display. This value cannot be null.

Returns
BiometricPrompt.Builder	This builder. This value cannot be null.

setDeviceCredentialAllowed

Added in API level 29
Deprecated in API level 30

public BiometricPrompt.Builder setDeviceCredentialAllowed (boolean allowed)

This method was deprecated in API level 30.
Replaced by setAllowedAuthenticators(int).

Optional: If enabled, the user will be given the option to authenticate with their device PIN, pattern, or password. Developers should first check BiometricManager.canAuthenticate(int) for Authenticators.DEVICE_CREDENTIAL before enabling. If the device is not secured with a credential, AuthenticationCallback.onAuthenticationError(int, CharSequence) will be invoked with BiometricPrompt.BIOMETRIC_ERROR_NO_DEVICE_CREDENTIAL. Defaults to false.

Note that enabling this option replaces the negative button on the prompt with one that allows the user to authenticate with their device credential, making it an error to call setNegativeButton(java.lang.CharSequence, java.util.concurrent.Executor, android.content.DialogInterface.OnClickListener).

Parameters
allowed	boolean: true if the prompt should fall back to asking for the user's device credential (PIN/pattern/password), or false otherwise.

Returns
BiometricPrompt.Builder	This builder. This value cannot be null.

setLogoBitmap

Added in API level 35

public BiometricPrompt.Builder setLogoBitmap (Bitmap logoBitmap)

Optional: Sets the bitmap drawable of the logo that will be shown on the prompt.

Note that using this method is not recommended in most scenarios because the calling application's icon will be used by default. Setting the logo is intended for large bundled applications that perform a wide range of functions and need to show distinct icons for each function.
Requires Manifest.permission.SET_BIOMETRIC_DIALOG_ADVANCED

Parameters
logoBitmap	Bitmap: A bitmap drawable of the logo that will be shown on the prompt. This value cannot be null.

Returns
BiometricPrompt.Builder	This builder. This value cannot be null.

setLogoDescription

Added in API level 35

public BiometricPrompt.Builder setLogoDescription (String logoDescription)

Optional: Sets logo description text that will be shown on the prompt.

Note that using this method is not recommended in most scenarios because the calling application's name will be used by default. Setting the logo description is intended for large bundled applications that perform a wide range of functions and need to show distinct description for each function.
Requires Manifest.permission.SET_BIOMETRIC_DIALOG_ADVANCED

Parameters
logoDescription	String: The logo description text that will be shown on the prompt. This value cannot be null.

Returns
BiometricPrompt.Builder	This builder. This value cannot be null.

Throws
IllegalArgumentException	If logo description is null.

setLogoRes

Added in API level 35

public BiometricPrompt.Builder setLogoRes (int logoRes)

Optional: Sets the drawable resource of the logo that will be shown on the prompt.

Note that using this method is not recommended in most scenarios because the calling application's icon will be used by default. Setting the logo is intended for large bundled applications that perform a wide range of functions and need to show distinct icons for each function.
Requires Manifest.permission.SET_BIOMETRIC_DIALOG_ADVANCED

Parameters
logoRes	int: A drawable resource of the logo that will be shown on the prompt.

Returns
BiometricPrompt.Builder	This builder. This value cannot be null.

setNegativeButton

Added in API level 28

public BiometricPrompt.Builder setNegativeButton (CharSequence text, 
                Executor executor, 
                DialogInterface.OnClickListener listener)

Required: Sets the text, executor, and click listener for the negative button on the prompt. This is typically a cancel button, but may be also used to show an alternative method for authentication, such as a screen that asks for a backup password.

Note that this setting is not required, and in fact is explicitly disallowed, if device credential authentication is enabled via setAllowedAuthenticators(int) or setDeviceCredentialAllowed(boolean).

Parameters
text	CharSequence: Text to be shown on the negative button for the prompt. This value cannot be null.
executor	Executor: Executor that will be used to run the on click callback. This value cannot be null. Callback and listener events are dispatched through this Executor, providing an easy way to control which thread is used. To dispatch events through the main thread of your application, you can use Context.getMainExecutor(). Otherwise, provide an Executor that dispatches to an appropriate thread.
listener	DialogInterface.OnClickListener: Listener containing a callback to be run when the button is pressed. This value cannot be null.

Returns
BiometricPrompt.Builder	This builder. This value cannot be null.

setSubtitle

Added in API level 28

public BiometricPrompt.Builder setSubtitle (CharSequence subtitle)

Optional: Sets a subtitle that will be shown on the prompt.

Parameters
subtitle	CharSequence: The subtitle to display. This value cannot be null.

Returns
BiometricPrompt.Builder	This builder. This value cannot be null.

setTitle

Added in API level 28

public BiometricPrompt.Builder setTitle (CharSequence title)

Required: Sets the title that will be shown on the prompt.

Parameters
title	CharSequence: The title to display. This value cannot be null.

Returns
BiometricPrompt.Builder	This builder. This value cannot be null.