你可以试试下面的代码
import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:local_auth/local_auth.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
final LocalAuthentication auth = LocalAuthentication();
_SupportState _supportState = _SupportState.unknown;
bool? _canCheckBiometrics;
List<BiometricType>? _availableBiometrics;
String _authorized = 'Not Authorized';
bool _isAuthenticating = false;
@override
void initState() {
super.initState();
auth.isDeviceSupported().then(
(isSupported) => setState(() => _supportState = isSupported
? _SupportState.supported
: _SupportState.unsupported),
);
}
Future<void> _checkBiometrics() async {
late bool canCheckBiometrics;
try {
canCheckBiometrics = await auth.canCheckBiometrics;
} on PlatformException catch (e) {
canCheckBiometrics = false;
print(e);
}
if (!mounted) return;
setState(() {
_canCheckBiometrics = canCheckBiometrics;
});
}
Future<void> _getAvailableBiometrics() async {
late List<BiometricType> availableBiometrics;
try {
availableBiometrics = await auth.getAvailableBiometrics();
} on PlatformException catch (e) {
availableBiometrics = <BiometricType>[];
print(e);
}
if (!mounted) return;
setState(() {
_availableBiometrics = availableBiometrics;
});
}
Future<void> _authenticate() async {
bool authenticated = false;
try {
setState(() {
_isAuthenticating = true;
_authorized = 'Authenticating';
});
authenticated = await auth.authenticate(
localizedReason: 'Let OS determine authentication method',
useErrorDialogs: true,
stickyAuth: true);
setState(() {
_isAuthenticating = false;
});
} on PlatformException catch (e) {
print(e);
setState(() {
_isAuthenticating = false;
_authorized = "Error - ${e.message}";
});
return;
}
if (!mounted) return;
setState(
() => _authorized = authenticated ? 'Authorized' : 'Not Authorized');
}
Future<void> _authenticateWithBiometrics() async {
bool authenticated = false;
try {
setState(() {
_isAuthenticating = true;
_authorized = 'Authenticating';
});
authenticated = await auth.authenticate(
localizedReason:
'Scan your fingerprint (or face or whatever) to authenticate',
useErrorDialogs: true,
stickyAuth: true,
biometricOnly: true);
setState(() {
_isAuthenticating = false;
_authorized = 'Authenticating';
});
} on PlatformException catch (e) {
print(e);
setState(() {
_isAuthenticating = false;
_authorized = "Error - ${e.message}";
});
return;
}
if (!mounted) return;
final String message = authenticated ? 'Authorized' : 'Not Authorized';
setState(() {
_authorized = message;
});
}
void _cancelAuthentication() async {
await auth.stopAuthentication();
setState(() => _isAuthenticating = false);
}
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: const Text('Plugin example app'),
),
body: ListView(
padding: const EdgeInsets.only(top: 30),
children: [
Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
if (_supportState == _SupportState.unknown)
CircularProgressIndicator()
else if (_supportState == _SupportState.supported)
Text("This device is supported")
else
Text("This device is not supported"),
Divider(height: 100),
Text('Can check biometrics: $_canCheckBiometrics\n'),
ElevatedButton(
child: const Text('Check biometrics'),
onPressed: _checkBiometrics,
),
Divider(height: 100),
Text('Available biometrics: $_availableBiometrics\n'),
ElevatedButton(
child: const Text('Get available biometrics'),
onPressed: _getAvailableBiometrics,
),
Divider(height: 100),
Text('Current State: $_authorized\n'),
(_isAuthenticating)
? ElevatedButton(
onPressed: _cancelAuthentication,
child: Row(
mainAxisSize: MainAxisSize.min,
children: [
Text("Cancel Authentication"),
Icon(Icons.cancel),
],
),
)
: Column(
children: [
ElevatedButton(
child: Row(
mainAxisSize: MainAxisSize.min,
children: [
Text('Authenticate'),
Icon(Icons.perm_device_information),
],
),
onPressed: _authenticate,
),
ElevatedButton(
child: Row(
mainAxisSize: MainAxisSize.min,
children: [
Text(_isAuthenticating
? 'Cancel'
: 'Authenticate: biometrics only'),
Icon(Icons.fingerprint),
],
),
onPressed: _authenticateWithBiometrics,
),
],
),
],
),
],
),
),
);
}
}
enum _SupportState {
unknown,
supported,
unsupported,
}