从 AngularFire2 5.0.0-rc.8 获取数据不显示

Question

在运行时，我能够从 Chrome 开发人员选项卡网络框架视图中获取数据，但它不会显示在控制台上。显示 "Hello" 警报，但不显示 "Inside" 警报，这很奇怪。有什么办法可以解决这个问题？

在app.module.ts中：

import { AngularFireModule } from 'angularfire2';
//import { AngularFireDatabase, FirebaseListObservable, FirebaseObjectObservable } from 'angularfire2/database-deprecated';
import { AngularFireDatabaseModule, AngularFireDatabase } from 'angularfire2/database'

const firebaseConfig = {
  apiKey: "AIzaSyClxpBtKaVlcr5n-itSoZM_WWTLBqVf-og",
  authDomain: "ionic-abs-conference.firebaseapp.com",
  databaseURL: "https://ionic-abs-conference.firebaseio.com",
  projectId: "ionic-abs-conference",
  storageBucket: "ionic-abs-conference.appspot.com",
  messagingSenderId: "668567626055"
};

内部进口：[...

AngularFireModule.initializeApp(firebaseConfig),
    AngularFireDatabaseModule,

在schedule.ts

import {  AngularFireDatabase } from 'angularfire2/database'

内部 class SchedulePage 构造函数

public angFire   : AngularFireDatabase

ionViewDidLoad里面

this.getDataFire();

然后

getDataFire()
  {
    alert("Hello");
    this.angFire.list('/speakers/0/').valueChanges().subscribe(
      data=> {
        //this.arrData= data;
        alert("Inside");
        console.log(JSON.stringify(data))
      }, (err) => {
        console.log(err);
      }
    )
  }

Answer 1

如果您尝试从 firebase 数据库中获取对象列表，请尝试以下操作：

import * as firebase from "firebase";
...
public list: Array<any> = [];
public listRef: firebase.database.Reference = firebase.database().ref('/speakers/0/');
...
this.listRef.on('value', itemSnapshot => {
  this.list = [];
  itemSnapshot.forEach( itemSnap => {
    this.list.push(itemSnap.val());
    return false;
  });
});

从 AngularFire2 5.0.0-rc.8 获取数据不显示

Fetch data from AngularFire2 5.0.0-rc.8 not displaying

javascript

ionic-framework

firebase-realtime-database

ionic3

angularfire5