我目前正在使用Flutter编写一些移动应用程序的代码。 我尝试使用gcloud库dart将数据发布/订阅到GCP Cloud Pub / Sub。这是main.dart的代码：
import 'dart:io';
import 'package:googleapis_auth/auth_io.dart' as auth;
import 'package:http/http.dart' as http;
import 'package:gcloud/db.dart';
import 'package:gcloud/storage.dart';
import 'package:gcloud/pubsub.dart';
import 'package:gcloud/service_scope.dart' as ss;
import 'package:gcloud/src/datastore_impl.dart' as datastore_impl;
Future<int> main() async {
// Read the service account credentials from the file.
var jsonCredentials = new File('path/file.json').readAsStringSync();
var credentials = new auth.ServiceAccountCredentials.fromJson(jsonCredentials);
// Get an HTTP authenticated client using the service account credentials.
var scopes = []
..addAll(PubSub.SCOPES);
var client = await auth.clientViaServiceAccount(credentials, scopes);
// Instantiate objects to access Cloud Datastore, Cloud Storage
// and Cloud Pub/Sub APIs.
var pubsub = new PubSub(client, 'project-name');
ss.fork(() {
// register the services in the new service scope.
registerPubSubService(pubsub);
// Run application using these services.
});
var topic = await pubsub.createTopic('flutter');
await topic.publishString('coba publish dr flutter');
var subscription =
await pubsub.createSubscription('sub_flutter', 'flutter');
var pullEvent = await subscription.pull();
print(pullEvent.message.asString);
await pullEvent.acknowledge();
return 0;
}
以下是 pubspec.yaml 文件中的依赖项：
dependencies:
flutter:
sdk: flutter
googleapis: ^0.54.0
googleapis_beta: ^0.49.0
googleapis_auth: ^0.2.10
gcloud: ^0.6.3
在尝试调试代码时，我遇到以下错误：
Launching lib\main.dart on vivo 1918 in debug mode...
Built build\app\outputs\apk\debug\app-debug.apk.
E/flutter (20586): [ERROR:flutter/shell/common/shell.cc(178)] Dart Error: error: import of dart:mirrors is not supported in the current Dart runtime
E/flutter (20586): [ERROR:flutter/shell/common/engine.cc(188)] Could not prepare to run the isolate.
E/flutter (20586): [ERROR:flutter/shell/common/engine.cc(127)] Engine not prepare and launch isolate.
E/flutter (20586): [ERROR:flutter/shell/common/shell.cc(407)] Could not launch engine with configuration.