无法使用 Flutter 应用程序访问 Firebase 后端

Question

I'm starting out with firebase and flutter. I want to start from working code, so I've implemented the baby names codelab. It worked. And then stopped working. I tried to update the codelab to use the latest versions of firestore. Still no longer working. This has happened to me with a different app. Even though I live in Thailand, my internet connection is pretty good.

this is the updated baby names codelab

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';


void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(MyApp());
}

final dummySnapshot = [
  {"name": "Filip", "votes": 15},
  {"name": "Abraham", "votes": 14},
  {"name": "Richard", "votes": 11},
  {"name": "Ike", "votes": 10},
  {"name": "Justin", "votes": 1},
];

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Baby Names',
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() {
    return _MyHomePageState();
  }
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Baby Name Votes')),
      body: _buildBody(context),
    );
  }

  Widget _buildBody(BuildContext context) {
    return StreamBuilder<QuerySnapshot>(
      stream: FirebaseFirestore.instance.collection('baby').snapshots(),
      builder: (context, snapshot) {
        if (!snapshot.hasData) return LinearProgressIndicator();

        return _buildList(context, snapshot.data.docs);
      },
    );
  }
  Widget _buildList(BuildContext context,  List<DocumentSnapshot> snapshot) {
    return ListView(
      padding: const EdgeInsets.only(top: 20.0),
      children: snapshot.map((data) => _buildListItem(context, data)).toList(),
    );
  }

  Widget _buildListItem(BuildContext context, DocumentSnapshot data) {
    final record = Record.fromSnapshot(data);

    return Padding(
      key: ValueKey(record.name),
      padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 8.0),
      child: Container(
        decoration: BoxDecoration(
          border: Border.all(color: Colors.grey),
          borderRadius: BorderRadius.circular(5.0),
        ),
        child: ListTile(
          title: Text(record.name),
          trailing: Text(record.votes.toString()),
            onTap: () => record.reference.update({'votes': FieldValue.increment(1)})

        ),
      ),
    );
  }
}

class Record {
  final String name;
  final int votes;
  final DocumentReference reference;

  Record.fromMap(Map<String, dynamic> map, {this.reference})
      : assert(map['name'] != null),
        assert(map['votes'] != null),
        name = map['name'],
        votes = map['votes'];

  Record.fromSnapshot(DocumentSnapshot snapshot)
      : this.fromMap(snapshot.data(), reference: snapshot.reference);

  @override
  String toString() => "Record<$name:$votes>";
}

this is the relevant section of pubspec.yaml

dependencies: flutter: sdk: flutter

cupertino_icons: ^1.0.0 cloud_firestore: ^0.14.3 firebase_core: ^0.5.2

here is the relevant (I hope) section from flutter run --verbose

[        ] I/ProviderInstaller(30660): Installed default security provider GmsCore_OpenSSL
[  +91 ms] D/ConnectivityManager(30660): requestNetwork; CallingUid : 10182, CallingPid : 30660
[  +76 ms] W/ware.baby_name(30660): Accessing hidden method Lsun/misc/Unsafe;->getObject(Ljava/lang/Object;J)Ljava/lang/Object; (greylist, linking, allowed)
[        ] W/ware.baby_name(30660): Accessing hidden method Lsun/misc/Unsafe;->putObject(Ljava/lang/Object;JLjava/lang/Object;)V (greylist, linking, allowed)
[+5234 ms] D/ViewRootImpl@7513633[MainActivity](30660): ViewPostIme pointer 0
[  +73 ms] D/ViewRootImpl@7513633[MainActivity](30660): ViewPostIme pointer 1
[+4565 ms] W/Firestore(30660): (22.0.0) [OnlineStateTracker]: Could not reach Cloud Firestore backend. Backend didn't respond within 10 seconds
[        ] W/Firestore(30660): 
[        ] W/Firestore(30660): This typically indicates that your device does not have a healthy Internet connection at the moment. The client will operate in offline mode until it is able to successfully connect to the backend.
[+5138 ms] D/ConnectivityManager(30660): unregisterNetworkCallback; CallingUid : 10182, CallingPid : 30660
[  +28 ms] W/Firestore(30660): (22.0.0) [WriteStream]: (eed8101) Stream closed with status: Status{code=UNAVAILABLE, description=Channel shutdownNow invoked, cause=null}.
[  +12 ms] W/DynamiteModule(30660): Local module descriptor class for providerinstaller not found.
[        ] W/Firestore(30660): (22.0.0) [WatchStream]: (78299e7) Stream closed with status: Status{code=UNAVAILABLE, description=Channel shutdownNow invoked, cause=null}.
[  +11 ms] I/DynamiteModule(30660): Considering local module providerinstaller:0 and remote module providerinstaller:0
[        ] W/ProviderInstaller(30660): Failed to load providerinstaller module: No acceptable module found. Local version is 0 and remote version is 0.
[   +9 ms] D/ConnectivityManager(30660): requestNetwork; CallingUid : 10182, CallingPid : 30660
[+15025 ms] D/ConnectivityManager(30660): unregisterNetworkCallback; CallingUid : 10182, CallingPid : 30660
[  +10 ms] W/Firestore(30660): (22.0.0) [WriteStream]: (eed8101) Stream closed with status: Status{code=UNAVAILABLE, description=Channel shutdownNow invoked, cause=null}.
[   +4 ms] W/Firestore(30660): (22.0.0) [WatchStream]: (78299e7) Stream closed with status: Status{code=UNAVAILABLE, description=Channel shutdownNow invoked, cause=null}.

I see the section where it says the backend didn't respond in 30 seconds and could indicate a bad internet connection. but there is nothing wrong with my internet. it has been working fine. To try and troubleshoot this, I originally set it up in southeast asia 2 because I'm in thailand. When it stopped workint the next day. i removed my project from firebase and rebuilt it in west coast usa. I also ran it with my vpn on in case that helped. I then removed the project and put it back in southeast asia. none of this had any impact on this error.

Answer 1

You might have just overlooked a step or messed something with the configuration at some point. Try to start another project from scratch and see if problem persists.

Answer 2

Problem solved. I tried to use my phone as a hot spot to test if it was my network. As soon as I did that, it started working.