Firebase 消息传递没有默认构造函数

Question

import 'package:flutter/material.dart';
import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';    
class PushNotificationService
{
final FirebaseMessaging firebaseMessaging = FirebaseMessaging();
Future initialize(context) async
{
firebaseMessaging.configure(
onMessage: (Map<String, dynamic> message) async {
retrieveRideRequestInfo(getRideRequestId(message), context);
},
onLaunch: (Map<String, dynamic> message) async {
retrieveRideRequestInfo(getRideRequestId(message), context);
},
onResume: (Map<String, dynamic> message) async {
retrieveRideRequestInfo(getRideRequestId(message), context);
},
);
}

清单：

<intent-filter>
<action android:name="FLUTTER_NOTIFICATION_CLICK" />
<category android:name="android.intent.category.DEFAULT" 
/>
</intent-filter>

错误：类"FirebaseMessaging"没有默认构造函数。请尝试使用"FirebaseMessaging"中定义的某个命名构造函数。

Answer 1

尝试FirebaseMessaging.instance而不是FirebaseMessaging()，它应该可以工作。

Answer 2

尝试添加依赖项firebase_core 1.4.0

import"package:firebase_core/firebase_core.dart"；

@override
void initState() {
// TODO: implement initState
super.initState();
Firebase.initializeApp();
}

onPressed: () async {
String token = await FirebaseMessaging.instance.getToken();
print(token);

},

Answer 3

使用FirebaseStorage.instanceFor而不是默认的构造函数

Answer 4

使用旧版本的FirebaseMessaging。我使用了firebase_messaging: ^4.0.0+1