错误类型错误：Observable_1.Observable.combineLatest 不是函数

Question

我正在使用 Angular 5.2 和 Rxjs 5.6-forward-compat.3。

我正在尝试合并两个 Firestore 集合，我认为问题与导入有关，但我尝试了所有可能的组合和选项，所以我不确定。

Here is the code:`IMPORTS: 
import 'rxjs/add/operator/mergeMap';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/combineLatest';

Here is my observable:
getActiveMedicationandCompliance(start: any): Observable<any[]> {
    const email = this.authService.getLoginUserid();
    const userDoc = this.afs.doc<User>(`users/${email}`);

    return userDoc
      .collection<any>(collection.MY_MEDICATION_CABINET, ref =>
        ref.where('active', '==', true).orderBy('medicationName', 'asc')
      )
      .snapshotChanges()
      .map(changes => {
        return changes.map(action => {
          let data = action.payload.doc.data();
          data.id = action.payload.doc.id;
          return userDoc
            .collection<any>(collection.MY_MEDICATION_COMPLIANCE, ref =>
              ref
                .where('medicationCabinetId', '==', data.id)
                .where('createdDate', '>=', start)
                .orderBy('createdDate', 'asc')
            )
            .snapshotChanges()
            .map(changes => {
              changes.map(action => {
                const dataCompliance = action.payload.doc.data();
                dataCompliance.id = action.payload.doc.id;
                return (data = Object.assign(
                  {},
                  { ...dataCompliance, ...data }
                ));
              });
            });
        });
      })
      .mergeMap(observables => Observable.combineLatest(observables));
  }
`

Answer 1

combineLatest 不是运算符，而是可观察导入的一部分：

import 'rxjs/observable/combineLatest';