角度：错误TS2322：类型'Observable <{}>'不可分配...使用share（）运算符

Question

I'm new to Angular 5 and I'm implementing the Observable/Observer pattern in order to share some events and some data changes to the subcribers.

Here the snippet of code:

...
@Injectable()
export class NidoService {
  ...
  event$: Observable<StrutturaDto[]>;
  private _observer: Observer<any>;

  event_dettaglio$: Observable<Struttura>;
  private _observer_dettaglio: Observer<any>;

  constructor() {
     this.event$ = new Observable(observer => this._observer = observer).share();
     this.event_dettaglio$ = new Observable(observer => this._observer_dettaglio = observer).share();
  }
  ...
}

When I try to build the application with ng build I get these errors on the two lines of code within the constructor :

ERROR in src/app/services/nido.service.ts(28,7): error TS2322: Type 'Observable<{}>' is not assignable to type 'Observable<StrutturaDto[]>'.
Type '{}' is not assignable to type 'StrutturaDto[]'.
Property 'includes' is missing in type '{}'.
src/app/services/nido.service.ts(29,7): error TS2322: Type 'Observable<{}>' is not assignable to type 'Observable<Struttura>'.
Type '{}' is not assignable to type 'Struttura'.
Property 'idStruttura' is missing in type '{}'.

When I use it in development mode I have no problems, but I cannot build without fixing them. How can I change the two lines of code?

Answer 1

You need to specify the type of observable:

this.event$ = new Observable<StrutturaDto[]>(observer => this._observer = observer).share();

and

this.event_dettaglio$ = new Observable<Struttura>(observer => this._observer_dettaglio = observer).share();