异步管道和ngFor不显示项

*ngFor 迭代 http.get

服务:

public getKeywords = () =>  {
   return this.http.get<getKeywords>(`${this.uri}/keywords`);
}

接口:

interface getKeywords {
  keywords: Array<object>;
}

电话号码:

export class KeywordsSettingsComponent implements OnInit {

  public currentKeywords$: any;

  constructor(private profileProvider: ProfileProvider) { }

  ngOnInit() {
    this.currentKeywords$ =
      this.profileProvider.getKeywords().pipe(map(({ keywords }) => keywords));
  }
}

<div class="row">
  <ng-template *ngIf="currentKeywords$ | async as currentKeywords ; else loading">
    <div class="keyword" * ngFor="let keywordObj of currentKeywords">
      {{ keywordObj.keyword }}
      <span class="icon-close"> </span>
    </div>
  </ng-template>
  <ng-template #loading> Loading keywords...</ng-template>
</div>

加载div未显示的事实表明没有发出值。如果我像这样订阅ngOnInt:

 this.currentKeywords$ = this.profileProvider.getKeywords().pipe(map(({keywords}) => keywords), share()).subscribe(res => res));

但是我知道异步管道管理订阅/取消订阅,所以在ngOnInit中订阅应该是不必要的。

结果来自http.get获取:

{..."keywords":[{"id":331,"keyword":"spam"},{"id":330,"keyword":"foo"},{"id":332,"keyword":"brexit"}]}