Angular和Firestore:在构造函数中获取UID用户身份验证以进行查询

import { Component, OnInit } from '@angular/core';
import { AngularFireAuth } from '@angular/fire/auth';
import { AngularFirestore } from '@angular/fire/firestore';

@Component({
  selector: 'app-example',
  templateUrl: './example.component.html',
  styleUrls: ['./example.component.css']
})
export class ExampleComponent implements OnInit {
  uid: string;

  constructor(private afAuth: AngularFireAuth, private firestore: AngularFirestore) { }

  ngOnInit(): void {
    this.afAuth.authState.subscribe(user => {
      if (user) {
        this.uid = user.uid;
        this.queryData();
      }
    });
  }

  queryData(): void {
    this.firestore.collection('data').doc(this.uid).get().subscribe(doc => {
      if (doc.exists) {
        // 处理查询结果
      } else {
        // 处理文档不存在的情况
      }
    });
  }
}