angular - ionic /Angular : The pipe 'async' could not be found

Question

当试图访问可观察的 holidayEntries$: Observable<HolidayEntry[]>在 html 中

<ion-list lines="full" *ngFor="let holiday of holidayEntries$ | async">
    <ion-label>
        <h1>{{ holiday.author }}</h1>
    </ion-label>
</ion-list>

我总是收到以下错误:

core.js:6228 ERROR Error: Uncaught (in promise):
Error: The pipe 'async' could not be found!

我读过 CommonModule可能会丢失，如 here 中所述，但我将其导入相应的.module.ts文件。
知道我做错了什么吗？
编辑:
我的模块

@NgModule({
  imports: [
    CommonModule,
    FormsModule,
    IonicModule,
    HolidaysPageRoutingModule
  ],
  declarations: [HolidaysPage]
})
export class HolidaysPageModule {}

我的组件

@Component({
  selector: 'app-tab2',
  templateUrl: './holidays.page.html',
  styleUrls: ['./holidays.page.scss'],
})
export class HolidaysPage implements OnInit {
  currentUser$: Observable<UserVM>;
  holidayEntries$: Observable<HolidayEntry[]>;

  constructor(
      private readonly appStore: Store<fromApp.State>,
      private readonly holidayStore: Store<fromHoliday.State>) {

    this.currentUser$ = appStore.select(fromAuth.selectAuthUser).pipe(
      map(user => new UserVM(user))
    );

    this.holidayEntries$ = holidayStore.select(fromHoliday.selectHolidayEntries)
  }

  loadHolidays() {
    console.log("loading holidays")
    this.holidayStore.dispatch(HolidayActions.loadHolidayRequests())
  }
}

Answer 1

如果您正在加载的路由上的组件未声明(通过声明:[])，那么您也会收到此类错误。从功能模块中删除功能组件的声明并添加到 app.module.ts (通过声明:[])