为什么我在Angular应用程序中遇到此错误？ 类型“可观察”不存在属性“ toPromise” <Response> “

Question

I am very new in Angular2/4 and I have some problem trying to follow this tutorial related to PrimeNG :

https://www.primefaces.org/primeng/#/schedule

I created the EventService class into a file in my prohject, in this way:

import {Injectable} from '@angular/core';
import {Http} from '@angular/http';

@Injectable()
export class EventService {

  constructor(private http: Http) {}

  getEvents() {
    return this.http.get('showcase/resources/data/scheduleevents.json')
      .toPromise()
      .then(res => <any[]> res.json().data)
      .then(data => { return data; });
  }
}

The problem is that WebStorm give me an error on the toPromise() method, it says:

Error:(11, 8) TS2339:Property 'toPromise' does not exist on type 'Observable<Response>'.

Why? What it means? What is the problem? How can I try to fix it?

Answer 1

您需要像这样导入运算符：

import 'rxjs/add/operator/toPromise';