Question

我试图从其他API获取一些数据，然后使用angular 4进行ngFor。当我尝试记录时，我的组件返回一个未定义的数据：

服务：

  getLatestFeed() {
    let promise = new Promise((resolve, reject) => {
      firebase.auth().currentUser.getIdToken(true).then((idToken) => {
        var headers = new HttpHeaders()
          .set('user_token', idToken);
        var params = new HttpParams()
          .set('page', '0')
          .set('hits', '6')
          .set('feed', 'latest');

        this.http.get('https://dev-api.byrd.news/v1/stories', { params, headers })
          .toPromise()
          .then(data => {
            return resolve(data);
          })
      }, error => {
        reject(error);
      })
    })
    return promise;
  }

}

组件：

export class DiscoverComponent implements OnInit {
  stories: any;

  constructor(private storiesService: StoriesService, private http: HttpClient) {
    this.storiesService.stories = this.stories;
  }



  ngOnInit(){

    this.stories = this.storiesService.getLatestFeed();
    console.log(this.stories);
  }

HTML：

<h1>DiscoverComponent</h1>

<div *ngFor="let story of stories">
  {{story.storyHeadline}}
</div>

我正在了解Observables和Promises之间的差异，并且我有点坚持这个。有任何想法吗？谢谢！

服务不会从API

0 个答案: