所以我导入了这个: import { Subject, Observer, Observable } from 'rxjs'; 我有这样一句话: public lessonList$: Observable<Lesson[]> = this.lessonListSubject.asObservable(); 但是我仍然得到这个错误: Type 'Observable<unknown>' is not assignableto type 'Observa
AngularFireAuth } from '@angular/fire/compat/auth';import { Observable} from 'rxjs'; providedIn: 'root'export class AuthService {
user$:Observable<fireba