我正在编写FLUTTER应用程序，并且试图将图像上传到Firebase存储上。这是我为重现错误而创建的简单测试应用。
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart' show rootBundle;
import 'package:path_provider/path_provider.dart';
import 'package:firebase_storage/firebase_storage.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
File image;
Future<File> getImageFileFromAssets(String path) async {
final byteData = await rootBundle.load('assets/$path');
final file = File('${(await getTemporaryDirectory()).path}/$path');
await file.writeAsBytes(byteData.buffer
.asUint8List(byteData.offsetInBytes, byteData.lengthInBytes));
return file;
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Test App'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Container(
height: 300,
width: 450,
child: image == null ? null : Image.file(image),
),
RaisedButton(
child: Text('Submit'),
onPressed: () async {
final fileName = 'imageName';
final firebaseStorageRef =
FirebaseStorage.instance.ref().child('userFolder');
final uploadTask =
firebaseStorageRef.child(fileName).putFile(image);
await uploadTask.onComplete;
},
),
RaisedButton(
child: Text('Load immagine'),
onPressed: () async {
image = await getImageFileFromAssets('test.jpg');
setState(() {});
},
),
],
),
),
);
}
}
如您所见，当我单击Load Image按钮时，我从资产中获取图像并将其存储在File对象中，并且效果很好。然后，当我想使用Submit按钮将该图像上传到Firebase的存储设备时，出现此错误：
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): Failed to handle method call
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.example.test_project. Make sure to call FirebaseApp.initializeApp(Context) first.
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): at com.google.firebase.FirebaseApp.getInstance(com.google.firebase:firebase-common@@17.0.0:234)
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): at com.google.firebase.storage.FirebaseStorage.getInstance(com.google.firebase:firebase-storage@@17.0.0:86)
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): at io.flutter.plugins.firebase.storage.FirebaseStoragePlugin.onMethodCall(FirebaseStoragePlugin.java:57)
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:222)
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): at io.flutter.embedding.engine.dart.DartMessenger.handleMessageFromDart(DartMessenger.java:96)
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): at io.flutter.embedding.engine.FlutterJNI.handlePlatformMessage(FlutterJNI.java:656)
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): at android.os.MessageQueue.nativePollOnce(Native Method)
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): at android.os.MessageQueue.next(MessageQueue.java:326)
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): at android.os.Looper.loop(Looper.java:160)
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): at android.app.ActivityThread.main(ActivityThread.java:6669)
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): at java.lang.reflect.Method.invoke(Native Method)
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
E/MethodChannel#plugins.flutter.io/firebase_storage(19436): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
E/flutter (19436): [ERROR:flutter/lib/ui/ui_dart_state.cc(148)] Unhandled Exception: PlatformException(error, Default FirebaseApp is not initialized in this process com.example.test_project. Make sure to call FirebaseApp.initializeApp(Context) first., null)
E/flutter (19436): #0 StandardMethodCodec.decodeEnvelope
package:flutter/…/services/message_codecs.dart:569
E/flutter (19436): #1 MethodChannel.invokeMethod
package:flutter/…/services/platform_channel.dart:316
E/flutter (19436): <asynchronous suspension>
E/flutter (19436): #2 _StorageFileUploadTask._platformStart
package:firebase_storage/src/upload_task.dart:130
E/flutter (19436): #3 StorageUploadTask._start
package:firebase_storage/src/upload_task.dart:35
E/flutter (19436): <asynchronous suspension>
E/flutter (19436): #4 StorageReference.putFile
package:firebase_storage/src/storage_reference.dart:65
E/flutter (19436): #5 _MyHomePageState.build.<anonymous closure>
package:test_project/main.dart:60
E/flutter (19436): <asynchronous suspension>
E/flutter (19436): #6 _InkResponseState._handleTap
package:flutter/…/material/ink_well.dart:654
E/flutter (19436): #7 _InkResponseState.build.<anonymous closure>
package:flutter/…/material/ink_well.dart:729
E/flutter (19436): #8 GestureRecognizer.invokeCallback
package:flutter/…/gestures/recognizer.dart:182
E/flutter (19436): #9 TapGestureRecognizer._checkUp
package:flutter/…/gestures/tap.dart:365
E/flutter (19436): #10 TapGestureRecognizer.handlePrimaryPointer
package:flutter/…/gestures/tap.dart:275
E/flutter (19436): #11 PrimaryPointerGestureRecognizer.handleEvent
package:flutter/…/gestures/recognizer.dart:455
E/flutter (19436): #12 PointerRouter._dispatch
package:flutter/…/gestures/pointer_router.dart:75
E/flutter (19436): #13 PointerRouter.route
package:flutter/…/gestures/pointer_router.dart:102
E/flutter (19436): #14 GestureBinding.handleEvent
package:flutter/…/gestures/binding.dart:218
E/flutter (19436): #15 GestureBinding.dispatchEvent
package:flutter/…/gestures/binding.dart:198
E/flutter (19436): #16 GestureBinding._handlePointerEvent
package:flutter/…/gestures/binding.dart:156
E/flutter (19436): #17 GestureBinding._flushPointerEventQueue
package:flutter/…/gestures/binding.dart:102
E/flutter (19436): #18 GestureBinding._handlePointerDataPacket
package:flutter/…/gestures/binding.dart:86
E/flutter (19436): #19 _rootRunUnary (dart:async/zone.dart:1136:13)
E/flutter (19436): #20 _CustomZone.runUnary (dart:async/zone.dart:1029:19)
E/flutter (19436): #21 _CustomZone.runUnaryGuarded (dart:async/zone.dart:931:7)
E/flutter (19436): #22 _invoke1 (dart:ui/hooks.dart:263:10)
E/flutter (19436): #23 _dispatchPointerDataPacket (dart:ui/hooks.dart:172:5)
E/flutter (19436):
数据库的规则是公共规则：
rules_version = '2';
service firebase.storage {
match /b/{bucket}/o {
match /{allPaths=**} {
allow read, write;
}
}
}
有人可以告诉我我在做什么错吗？
答案 0 :(得分：6)
根据文档，只需更改您的主要方法：
Future<void> main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp(MyApp());
}
答案 1 :(得分：1)
所有Firebase版本均已更新，现在您必须在使用任何Firebase产品之前调用Firebase.initializeApp（），例如：
首先，所有Firebase产品现在都取决于firebase_core版本（0.5.0+），因此您需要将其添加到pubspec.yaml文件中：
dependencies:
flutter:
sdk: flutter
firebase_core : ^0.5.0
然后您必须调用Firebase.initializeApp（）：
在main.dart中：
Future<void> main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp(); //Make sure you imported firebase_core
runApp(MaterialApp(
home: GettingStartedPage(),
));
}
答案 2 :(得分：0)
答案 3 :(得分：0)
对于谁来这里，我解决了这个问题。有很多事情要做，例如将您的应用程序添加到Firebase项目中并编辑一些文件。 唯一要做的是更好地阅读文档并遵循所有步骤： Add Firebase to your Flutter app
答案 4 :(得分：0)
import'package：firebase_core / firebase_core.dart';