How To Use Face Id Auth Using Flutter Android App

Posted By Bajarangi soft , Posted On 27-11-2020

Local Authentication is an important verification step for several apps. This verification is fully done on device, so there is no way of leaking any sensitive information to any third-party servers.

How To Use Face Id Auth Using Flutter Android App

Face Id Auth
Step 1
We cannot directly remove the time stamp from Face Id Auth but using the intl.dart package we can easily filter the date stamp from time stamp. So open your flutter project’s pubspec.yaml in code .

dependencies:
  flutter:
    sdk: flutter
  local_auth: ^0.6.3+4

Step 2
After done saving the pubspec.yaml file, Open your flutter project root folder in Command Prompt or Terminal and execute flutter pub get command.

flutter pub get

Complete Code For Face Id Auth In Flutter
main.dart

import 'package:local_auth/auth_strings.dart';
import 'package:local_auth/local_auth.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);
  final String title;
  @override
  _MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
  final LocalAuthentication localAuth = LocalAuthentication();
  bool _canCheckBiometric = false;
  String _authorizeText = 'Not Authorized!';

  List<BiometricType> availableBiometrics = List<BiometricType>();

  Future<void> _authorize() async {
    bool _isAuthorized = false;
    try {
      const iosStrings = const IOSAuthMessages(
          cancelButton: 'Cancel Auth',
          goToSettingsButton: 'Goto Settings',
          goToSettingsDescription: 'Please set up your Touch ID.',
          lockOut: 'Please re-enable your Touch ID');

      _isAuthorized = await localAuth.authenticateWithBiometrics(
          localizedReason: 'Please authenticate to Complete this process',
          useErrorDialogs: false,
          iOSAuthStrings: iosStrings);
    } on PlatformException catch (e) {
      print(e);
    }

    if (!mounted) return;

    setState(() {
      if (_isAuthorized) {
        _authorizeText = "Authorized Successfully!";
      } else {
        _authorizeText = "Not Authorized!";
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.red[900],
          title: Text('Face ID Auth Example')),
      body: Center(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.center,
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Padding(
                padding: const EdgeInsets.all(8.0),
                child: Text(_authorizeText),
              ),
              RaisedButton(
                child: Text('Authorize'),
                color: Colors.red,
                textColor: Colors.white,
                onPressed: _authorize,
              )
            ],
          )),
    );
  }
}