main.dart

import 'package:biometric_authenticator/biometric_authenticator.dart';
import 'package:flutter/material.dart';
import 'package:fluttertoast/fluttertoast.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Biometric Authentication Demo',
      theme: ThemeData(
        primarySwatch: Colors.indigo,
      ),
      home:  MyHomePage(title: 'Login using Biometric Method'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  String title;
  MyHomePage({super.key, required this.title});

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  bool isSupported = false;
  bool? isAuthenticated;
  @override
  void initState() {
    biometricLogin();
    super.initState();
  }

  biometricLogin() async {
    isSupported = await BiometricAuthentication().isDeviceSupported();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar:AppBar(
        automaticallyImplyLeading: false,
        title:  Text(widget.title),
        toolbarHeight: 80,
        shape: Border.symmetric(horizontal: BorderSide(color: Theme.of(context).primaryColor)),
      ),
      body: Center(
        child: InkWell(
          onTap: () async {
            if(isSupported){
              // BiometricAuthentication package usage for authenticate
              isAuthenticated = await BiometricAuthentication().authenticate(title: 'Authenticate to Login');
              if(isAuthenticated!){
                // write your logic for successful authentication
                Fluttertoast.showToast(msg: 'Login Successful');
              }else{
                Fluttertoast.showToast(msg: 'Login failed!!! Try Again');
              }
            }else{
              Fluttertoast.showToast(msg: 'Device not supports Biometric Auth');
            }