如何在Angularjs2中设置初始观察值？

import { Component, OnInit } from '@angular/core';
import { Observable, BehaviorSubject } from 'rxjs';

@Component({
  selector: 'app-example',
  templateUrl: './example.component.html',
  styleUrls: ['./example.component.css']
})
export class ExampleComponent implements OnInit {
  // 创建一个BehaviorSubject对象，并设置初始值为null
  private initialValueSubject: BehaviorSubject<any> = new BehaviorSubject<any>(null);
  // 将BehaviorSubject对象转换为Observable对象
  public initialValue$: Observable<any> = this.initialValueSubject.asObservable();

  constructor() { }

  ngOnInit(): void {
    // 在ngOnInit中，可以通过next方法设置初始观察值
    this.initialValueSubject.next('Initial value');
  }
}

<p>{{ initialValue$ | async }}</p>