如何合并local_auth进行指纹认证？

Question

我想使用local_auth合并指纹认证，但不能。您能否在我的代码中提供帮助，以便指纹验证后进入MyHomePage。 提前致谢。我已经在local_auth上尝试了他们的示例，但没有获得使用方法。

我不介意是否需要2个屏幕。

    import 'dart:io';        
    import 'package:expense_planner/screens/edit_transaction.dart';
    import 'package:expense_planner/screens/new_transaction.dart';
    import 'package:expense_planner/services/service_locator.dart';
    import 'package:expense_planner/widgets/chart.dart';
    import 'package:expense_planner/widgets/transaction_list.dart';
    import 'package:flutter/cupertino.dart';
    import 'package:flutter/material.dart';
    import 'package:provider/provider.dart';
    import 'package:flutter/services.dart';
    
    import 'providers/transactions.dart';
    
    void main() {
      WidgetsFlutterBinding.ensureInitialized();
      SystemChrome.setPreferredOrientations([
        DeviceOrientation.portraitUp,
        DeviceOrientation.portraitDown,
      ]);
      setupLocator();
    
      runApp(MyApp());
    }
    
    class MyApp extends StatelessWidget {
      @override
      Widget build(BuildContext context) {
        return ChangeNotifierProvider.value(
          value: Transactions(),
          child: MaterialApp(
            title: 'Expense Tracker',
            theme: ThemeData(
              primarySwatch: Colors.red,
              accentColor: Colors.black54,
              fontFamily: 'OpenSans',
              textTheme: ThemeData.light().textTheme.copyWith(
                    headline6: TextStyle(
                      fontFamily: 'OpenSans',
                      color: Colors.black54,
                      fontWeight: FontWeight.bold,
                    ),
                    headline5: TextStyle(
                      fontFamily: 'OpenSans',
                      color: Colors.white,
                      fontWeight: FontWeight.bold,
                    ),
                    button: TextStyle(color: Colors.white),
                  ),
              appBarTheme: AppBarTheme(
                textTheme: ThemeData.light().textTheme.copyWith(
                      headline5: TextStyle(
                        color: Colors.white,
                        fontFamily: 'OpenSans',
                        fontWeight: FontWeight.bold,
                      ),
                    ),
              ),
            ),
            home: MyHomePage(),
            routes: {
              EditTransaction.routeName: (ctx) => EditTransaction(),
            },
          ),
        );
      }
    }
    
    class MyHomePage extends StatefulWidget {
      @override
      _MyHomePageState createState() => _MyHomePageState();
    }
    
    class _MyHomePageState extends State<MyHomePage> {
      void _startAddNewTransaction(BuildContext ctx) {
        showModalBottomSheet(
          context: ctx,
          builder: (_) {
            return GestureDetector(
              onTap: () {},
              child: NewTransaction(),
            );
          },
        );
      }
    
      Widget _buildAppBar() {
        return Platform.isIOS
            ? CupertinoNavigationBar(
                middle: Text(
                  'Expense Tracker',
                  style: Theme.of(context).textTheme.headline5,
                ),
                trailing: Row(
                  mainAxisSize: MainAxisSize.min,
                  children: <Widget>[
                    GestureDetector(
                      child: Icon(CupertinoIcons.add),
                      onTap: () => _startAddNewTransaction(context),
                    ),
                  ],
                ),
              )
            : AppBar(
                title: Text(
                  'Expense Tracker',
                  style: Theme.of(context).textTheme.headline5,
                ),
                actions: <Widget>[
                  IconButton(
                    icon: Icon(Icons.add),
                    onPressed: () => _startAddNewTransaction(context),
                  ),
                ],
              );
      }
    
      @override
      Widget build(BuildContext context) {
        final mediaQuery = MediaQuery.of(context);
        // final isLandscape = mediaQuery.orientation == Orientation.landscape;
        final PreferredSizeWidget appBar = _buildAppBar();
    
        final pageBody = SafeArea(
          child: SingleChildScrollView(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: <Widget>[
                Container(
                  height: (mediaQuery.size.height -
                          appBar.preferredSize.height -
                          mediaQuery.padding.top) *
                      0.3,
                  child: Chart(),
                ),
                Container(
                  height: (mediaQuery.size.height -
                          appBar.preferredSize.height -
                          mediaQuery.padding.top) *
                      0.7,
                  child: TransactionList(),
                )
              ],
            ),
          ),
        );
        return Platform.isIOS
            ? CupertinoPageScaffold(
                navigationBar: appBar,
                child: pageBody,
              )
            : Scaffold(
                appBar: appBar,
                body: pageBody,
                floatingActionButtonLocation:
                    FloatingActionButtonLocation.centerFloat,
                floatingActionButton: Platform.isIOS // checking is platform is IOS
                    ? Container() // we r avoiding floatingActionButton
                    : FloatingActionButton(
                        child: Icon(Icons.add),
                        onPressed: () => _startAddNewTransaction(context),
                      ),
              );
      }
    }