Flutter：错误：“对象”类型的值？无法分配给“输出？”类型的变量

Question

我仍然是 Flutter 新手，最近我刚刚在我的计算机上下载了最新的 Flutter 版本，但每次我尝试运行我的项目时都会收到此错误：

C:\Users\khomo\OneDrive\Documents\GitHub\luvart-Project\.dart_tool\flutter_build\99035e6341f80e4f3744d732501fdc7d\native_assets.yaml --verbosity=error package:luvart/main.dart
[+11601 ms] [+11647 ms] ../../../../AppData/Local/Pub/Cache/hosted/pub.dev/smithy-0.5.2/lib/src/http/http_operation.dart:271:16: Error: A value of type 'Object?' can't be assigned to a variable of type 'Output?'.
[  +36 ms] [   +4 ms]  - 'Object' is from 'dart:core'.
[        ] [        ]       output = switch (payload) {
[        ] [        ]                ^ 

我不太确定错误在我的

 main.dart

文件中的位置或如何修复它，或者即使错误确实存在。这是我的

main.dart

文件的外观：

import 'package:amplify_api/amplify_api.dart';
import 'package:amplify_auth_cognito/amplify_auth_cognito.dart';
import 'package:amplify_datastore/amplify_datastore.dart';
import 'package:amplify_flutter/amplify_flutter.dart';
import 'package:amplify_storage_s3/amplify_storage_s3.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:luvart/amplifyconfiguration.dart';
import 'package:luvart/entry_point.dart';

import 'models/ModelProvider.dart';

void main() {
  runApp(
    const ProviderScope(
      child: MyApp(),
    ),
  );
}

class MyApp extends ConsumerStatefulWidget {
  const MyApp({super.key});

  @override
  ConsumerState<MyApp> createState() => _MyAppState();
}

class _MyAppState extends ConsumerState<MyApp> {
  bool isAmplifyConfigured = false;

  @override
  void initState() {
    super.initState();
    _configAmplify();
  }

  Future<void> _configAmplify() async {
    try {
      await Amplify.addPlugins(
        [
          AmplifyAPI(),
          AmplifyAuthCognito(),
          AmplifyDataStore(modelProvider: ModelProvider.instance),
          AmplifyStorageS3(),
        ],
      );

      await Amplify.configure(amplifyconfig);

      setState(() {
        isAmplifyConfigured = true;
      });
    } on Exception catch (e) {
      if (kDebugMode) {
        print('$e');
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'luvart',
      themeMode: ThemeMode.light,
      theme: ThemeData(
        useMaterial3: true,
        visualDensity: VisualDensity.adaptivePlatformDensity,
        primaryColor: Colors.black,
        scaffoldBackgroundColor: Colors.white,
        appBarTheme: const AppBarTheme(
          backgroundColor: Colors.white,
          elevation: 0.0,
        ),
      ),
      home: isAmplifyConfigured == false
          ? const Scaffold(
              body: Center(
                child: CircularProgressIndicator(),
              ),
            )
          : const EntryPoint(),
    );
  }
}

请提前帮忙并致谢

Answer 1

您使用的 smithy 库版本已过时。请使用

smithy

版本 ->

0.6.1

这可以修复您遇到的错误。参考： https://github.com/aws-amplify/amplify-flutter/commit/6ab1a671273fd8573875faad1b2f3ae8a616227a