我對 Angular 9 還很陌生。我有一個(gè)程序，用戶輸入一個(gè)名稱 - 在提交時(shí) - 發(fā)送一個(gè) POST HTTP 請求并存儲該名稱。然后，我有一個(gè)不相關(guān)的子標(biāo)題組件，它列出了使用 ngOnInit() 的 GET HTTP 請求存儲的名稱。但是，我需要子標(biāo)題在每次輸入新列表時(shí)動(dòng)態(tài)更新該名稱列表，而不僅僅是在組件實(shí)例化時(shí)。我不確定如何進(jìn)行。我確信我可以簡單地添加一個(gè)按鈕來獲取和更新所述列表，但嘗試更動(dòng)態(tài)的東西。提前致謝！//SERVICE.TS...import { Injectable } from '@angular/core';import { HttpClient } from '@angular/common/http';import { NewList } from './new-list.model';import { map } from 'rxjs/operators';@Injectable({  providedIn: 'root'})export class ListService {  createdLists: NewList[] = [];  constructor(private http: HttpClient) { }  createList(postData) {    return this.http      .post(        'API_KEY',        postData      );  }  getLists() {    return this.http      .get<NewList>(        'API_KEY'      ).pipe(map(responseData => {            const responseArray: NewList[] = [];            for (const key in responseData) {              responseArray.push(responseData[key])            }            return responseArray;          })        );  }}// NEW-LIST-MENU.TS (USER ENTERS A NAME)...import { Component, OnInit } from '@angular/core';import { NgForm } from '@angular/forms';import { Router } from '@angular/router';import { ListService } from 'src/app/shared/list.service';import { NewList } from 'src/app/shared/new-list.model';import { UIService } from 'src/app/shared/ui.service';@Component({  selector: 'app-new-list-menu',  templateUrl: './new-list-menu.component.html',  styleUrls: ['./new-list-menu.component.css']})export class NewListMenuComponent implements OnInit {  constructor(private listService: ListService,              private uiService: UIService,              private router: Router) { }  ngOnInit(): void {  }  onSubmit(form: NgForm) {    const listName = form.value.listname;    const newListObj = new NewList(listName, []);        this.listService.createList(newListObj)      .subscribe(() => {        this.router.navigate(['']);      });    const lists = this.listService.updateLists(newListObj);            form.reset();  }