Flutter Fingerprint Authentication

dependencies:
  local_auth: ^0.6.1

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


class TouchID extends StatefulWidget {
  @override
  _TouchIDState createState() => _TouchIDState();
}

class _TouchIDState extends State<TouchID> {
  final LocalAuthentication localAuth = LocalAuthentication();
  bool _canCheckBiometric = false;
  String _authorizeText = 'Not Authorized!';

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

  Future<void> _authorize() async {
    bool _isAuthorized = false;
    try {
      _isAuthorized = await localAuth.authenticateWithBiometrics(
        localizedReason: 'Please authenticate to Complete this process',
        useErrorDialogs: true,
        stickyAuth: true,
      );
    } 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(title: Text('Touch 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,style: TextStyle(color: Colors.black38,fontSize: 20),),
              ),
              RaisedButton(
                child: Text('Authorize',style: TextStyle(color: Colors.white,fontSize: 20),),
                color: Colors.pink,
                onPressed: _authorize,
              )
            ],
          )),
    );
  }
}

class MainActivity: FlutterFragmentActivity() {
    override fun configureFlutterEngine( flutterEngine: FlutterEngine) {
        GeneratedPluginRegistrant.registerWith(flutterEngine);
    }
}

void main() => runApp(MyApp());

class MyApp extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return MaterialApp(
      theme: ThemeData(
        primaryColor: Colors.pink
      ),
      home: TouchID(),
    );
  }

}