如何使用Ionic4/Angular检索嵌套Firestore数据库中所有用户的数据

npm install firebase @angular/fire --save

import { AngularFireModule } from '@angular/fire';
import { AngularFirestoreModule } from '@angular/fire/firestore';

const firebaseConfig = {
  // 将你的Firebase配置信息填写在这里
};

@NgModule({
  imports: [
    AngularFireModule.initializeApp(firebaseConfig),
    AngularFirestoreModule
  ],
  // ...
})
export class AppModule { }

import { Component } from '@angular/core';
import { AngularFirestore } from '@angular/fire/firestore';

@Component({
  selector: 'app-users',
  templateUrl: './users.component.html',
  styleUrls: ['./users.component.scss']
})
export class UsersComponent {
  users: any[];

  constructor(private firestore: AngularFirestore) { }

  retrieveUsers() {
    this.firestore.collection('users').valueChanges().subscribe(users => {
      this.users = users;
    });
  }
}

<div *ngFor="let user of users">
  <p>{{ user.name }}</p>
  <p>{{ user.email }}</p>
  <!-- 显示其他用户属性 -->
</div>

<button (click)="retrieveUsers()">检索用户数据</button>