7.http请求

A.app.module.ts
导入

配置

B.app.component.ts

...
import{HttpClient} from '@angular/common/http'
...
export class AppComponent {
  title = 'my-app';
  //在构造函数中注册
  constructor(public http:HttpClient){}
  //组件初始化触发
  ngOnInit(){
    var url:string="http://localhost:8000/top250";
    this.http.get(url).subscribe(res=>{
      console.log(res);
    })
  }
}