Angular中的“No provider for HttpClient”错误：原因与修复

你好！我是Angular和TypeScript的新手。我尝试在我的应用中向API发送HTTP请求，但在运行时遇到了以下错误： ``` NullInjectorError: No provider for HttpClient! ``` 这是我的代码。`DataService`服务： ```typescript import { Injectable } from '@angular/core'; import { HttpClient } from '@angular/common/http'; @Injectable() export class DataService { constructor(private http: HttpClient) {} getPosts() { return this.http.get('https://jsonplaceholder.typicode.com/posts'); } } ``` `AppComponent`组件： ```typescript import { Component, OnInit } from '@angular/core'; import { DataService } from './data.service'; @Component({ selector: 'app-root', template: '' }) export class AppComponent implements OnInit { posts: any[] = []; constructor(private dataService: DataService) {} ngOnInit() { this.dataService.getPosts().subscribe((data: any) => {