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试图从https://dart.academy/build-a-real-time-chat-web-app-with-dart-angular-2-and-firebase-3/学习,但在实施在角填充火力地堡数据库的名单达特
firebase_service.dart
import 'package:angular/angular.dart';
import 'package:firebase/firebase.dart' as fb;
import 'package:yns_admin/category_component/category.dart';
@Injectable()
class FirebaseService {
fb.Database fbDatabase;
fb.DatabaseReference databaseReference;
List<Category> categories;
FirebaseService() {
fb.initializeApp(
apiKey: "AIzaSyBOShlCgUeqTL99n32ssasasasasa",
authDomain: "yns-app.firebaseapp.com",
databaseURL: "https://yns-app.firebaseio.com",
storageBucket: "yns-app.appspot.com",
);
fbDatabase = fb.database();
databaseReference = fbDatabase.ref("categories");
}
void showCategories() {
categories = [];
databaseReference.onChildAdded.listen(newCategory);
}
void newCategory(fb.QueryEvent event) {
Category category = new Category.fromMap(event.snapshot.val());
categories.add(category);
}
}
地图代码来自 category.dart
class Category {
final String categoryTitle;
Category(this.categoryTitle);
Category.fromMap(Map map, this.categoryTitle) {}
Map toMap() =>{
"categoryTitle":categoryTitle
};
}
main.dart
import 'package:angular/angular.dart';
import 'package:yns_admin/app_component/app_component.dart';
void main() {
bootstrap(AppComponent);
}
'fromMap()'从哪里来?你在使用'json_serializable'包吗? –
我已经添加了category.dart的地图代码 –
您的'fromMap(...)'需要2个值,但您只传递一个'event.snapshot.val()'。你的'fromMap(...)'似乎对预期的'Map'参数没有任何作用。 –