如何在单击本地身份验证中的“取消”时以及在最大尝试次数超过波动时如何关闭应用程序

问题描述

我是新手。我想创建一个使用本地生物特征识别的应用程序，并且需要帮助

1. 单击local_auth中的“取消”按钮关闭应用程序，
2. 尝试最多后关闭应用程序。
3. 暂停后台直到身份验证完成

我的代码是

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',),);
  }
}

有人请帮我解决这3个问题。

解决方法

你可以像这样取消点击关闭应用

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

只是为了让您知道 exit(0) 需要导入 dart:io