如何在本地身份验证中单击取消以及在颤振中超过最大尝试次数时关闭应用程序

Question

I'm new in flutter. I wanted to create an application with local biometrics I have used local auth and i need to have help with

1. close the application on the click of cancel button in local_auth,
2. close the application when maximum tries are done.
3. pause the background untill authentication complete

my code is

import 'dart:async';
import 'package:LogInSignIn.dart';
import 'package:flutter/material.dart';
import 'package:cashhub/homescreen.dart';
import 'package:local_auth/local_auth.dart';
import 'package:flutter/services.dart';

void main() {
  setupLocator();
  runApp(new MaterialApp(
    debugShowCheckedModeBanner: false,
    home: new SplashScreen(),
    routes: <String, WidgetBuilder>{
      '/HomeScreen': (BuildContext context) => new LogInSignIn(),
      

    },
  ));
}

class SplashScreen extends StatefulWidget {
  @override
  _SplashScreenState createState() => new _SplashScreenState();
}

class _SplashScreenState extends State<SplashScreen> {
  //final LocalAuthenticationService _localAuth = locator<LocalAuthenticationService>();
  final LocalAuthentication auth = LocalAuthentication();
  bool _canCheckBiometrics;
  List<BiometricType> _availableBiometrics;
  String _authorized = 'Not Authorized';
  bool _isAuthenticating = false;

  startTime() async {
    var _duration = new Duration(seconds: 4);
    return new Timer(_duration, navigationPage);
  }




  Future<void> _authenticate() async {
    bool authenticated = false;
    try {
      setState(() {
        _isAuthenticating = true;
        _authorized = 'Authenticating';
      });
      authenticated = await auth.authenticateWithBiometrics(
          localizedReason: 'Scan your fingerprint to authenticate',
          useErrorDialogs: true,
          stickyAuth: true);
      setState(() {
        _isAuthenticating = false;
        _authorized = 'Authenticating';
      });
    } on PlatformException catch (e) {
      print(e);
    }
    if (!mounted) return;

    final String message = authenticated ? 'Authorized' : 'Not Authorized';
    // if( message == "Not Authorized"){
    //   SystemNavigator.pop();
    // }
    setState(() {
      _authorized = message;
    });

  }

  void navigationPage() {
    Navigator.of(context).pushReplacementNamed('/HomeScreen');
  }
  @override
  void initState() {
    _authenticate();
    //autho();
    super.initState();

    startTime();

  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      body: new Center(
        child: new Image.asset('assets/splashlogo.png',
        ),
      ),
    );
  }
}

anyone please help me with this 3 queries..

Answer 1

you can close the app with cancel click like this

setState(() {
  if (isAuthorized) {
    _authorizedOrNot = "Authorized";
  } else {
    _authorizedOrNot = "Not Authorized";
    exit(0);
  }
});

just so you know exit(0) need to impot dart:io