在 app.module.ts 中引入 HttpClientModule 并注入

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

Angular get 请求数据
在用到的地方引入 HttpClient 并在构造函数声明

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

get 请求数据

    var api = "http://a.itying.com/api/productlist";
    this.http.get(api).subscribe(response => {
      console.log(response);
    });`在这里插入代码片`

Angular post 提交数据
在用到的地方引入 HttpClient、HttpHeaders 并在构造函数声明 HttpClient

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

post 提交数据

    const httpOptions = {
      headers: new HttpHeaders({ 'Content-Type': 'application/json' })
    };
    var api = "http://127.0.0.1:3000/doLogin";
    this.http.post(api,{username:'张三',age:'20'},httpOptions).subscribe(response => {
      console.log(response);
    });

Angular Jsonp 请求数据
在 app.module.ts 中引入 HttpClientModule、HttpClientJsonpModule 并注入


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

在用到的地方引入 HttpClient 并在构造函数声明

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

jsonp 请求数据

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

Angular 中使用第三方模块 axios 请求数据
安装 axios

cnpm install axios --save

用到的地方引入 axios

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

封装service作为http服务

    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)
              });
        })
    
      }  
    }