import {HttpClientModule} from '@angular/common/http';imports: [ BrowserModule, HttpClientModule]

import {HttpClient} from "@angular/common/http";constructor(public http:HttpClient) { }

var api = "http://a.itying.com/api/productlist";this.http.get(api).subscribe(response => { console.log(response);});

import {HttpClient,HttpHeaders} from "@angular/common/http";constructor(public http:HttpClient) { }

const httpOptions = { headers: new HttpHeaders({ 'Content-Type': 'application/json' })};var api = "http://127.0.0.1:3000/doLogin";this.http.post(api,{username:'張三',age:'20'},httpOptions).subscribe(response => { console.log(response);});

import {HttpClientModule,HttpClientJsonpModule} from'@angular/common/http';imports: [ BrowserModule, HttpClientModule, HttpClientJsonpModule]

import {HttpClient} from "@angular/common/http";constructor(public http:HttpClient) { }

var api = "http://a.itying.com/api/productlist";this.http.jsonp(api,'callback').subscribe(response => {console.log(response);});

cnpm install axios --save

import axios from 'axios';axios.get('/user?ID=12345').then(function (response) {// handle successconsole.log(response);}).catch(function (error) {// handle errorconsole.log(error);}).then(function () {// always executed});

import { Injectable } from '@angular/core';import axios from 'axios';@Injectable({ providedIn: 'root'})export class HttpserviceService { constructor() { } axiosGet(api){   return new Promise((resolve,reject)=>{    axios.get(api)     .then(function (response) {      // handle success         resolve(response)     });  }) } }