角度继承注入不同的实例

Question

我有2个相同的组件。唯一的区别是他们的名字和一些HTML标题。因为我想使用继承。

我创建了一个抽象服务：

export abstract class AbstractFilmListService {

  protected readonly API = WebUtils.RESOURCE_HOST_API + 'film/';


  constructor(protected client: HttpClient) {
  }

  deleteFilm(filmId: number) {
    return this.client.delete(this.API + filmId);
  }

  fetchFilms(): Observable<Film[]> {
    return this.client.get(this.API) as Observable<Film[]>;
  }
}

子类1：

@Injectable({
  providedIn: 'root'
})
export class FilmListService extends AbstractFilmListService {
  constructor(protected client: HttpClient) {
    super(client);
  }
}

子类2：

@Injectable({
  providedIn: 'root'
})
export class SeriesListService extends AbstractFilmListService{

  protected readonly API: string;

  constructor(client: HttpClient) {
    super(client);
    this.API = WebUtils.SERIES_API;
  }
}

到目前为止一切都很好。但我想用组件做同样的事情：

FilmListComponent：

@Component({
  selector: 'app-film-list',
  templateUrl: './film-list.component.html',
  styleUrls: ['./film-list.component.css']
})
export class FilmListComponent implements OnInit {

  constructor(protected client: HttpClient,
              protected router: Router,
              protected snackService: SnackService,
              protected filmListService: FilmListService // <- Problem is here !
              ) {
  }
//....

}

SeriesListComponent：

 @Component({
  selector: 'app-series-list',
  templateUrl: './series-list.component.html',
  styleUrls: ['./series-list.component.css']
})
export class SeriesListComponent extends FilmListComponent implements OnInit {

  constructor(protected client: HttpClient,
              protected router: Router,
              protected snackService: SnackService,
              protected filmListService: FilmListService // <- Problem is here!
  ) {
    super(client, router, snackService, filmListService);
  }

  ngOnInit() {
  }

}

我想FilmListComponent声明AbstractFilmListService而不是FilmListService，当它开始注入服务时，它应该注入FilmListService。

同样的方式qazxsw poi应该声明qazxsw poi而不是qazxsw poi，当它开始注入服务时它应该注入SeriesListComponent。

我的意思是这样的：

AbstractFilmListService

对于SeriesListComponent也是如此：

FilmListService

我知道Angular不为每个使用Singleton Design Pattern for Dependency Injection的组件创建新的服务。为了弄清楚自己，我写了

SeriesListService

如何为不同的组件注入不同的实例，即使它们的类型在constuructor中声明相同？

---

更新

的AppModule：

export class FilmListComponent implements OnInit {

  constructor(
             // ...
              protected filmListService: AbstractFilmListService
              ) {
          this.filmListService = new FilmListService(); // Angular should do  something like this...
  }
//....

}

Answer 1

如果它不是单身人士服务，那么在我看来使用

export class SeriesListComponent implements OnInit {

  constructor(
             // ...
              protected filmListService: AbstractFilmListService
              ) {
          this.filmListService = new SeriesListService(); // Angular should do  something like this...
  }
//....

}

并没有多大意义。

但是要回答你的问题，如果你想要这个服务的不同实例，你应该在"new SeriesListService(), new FilmListService()" 注释中提供服务：

@NgModule({
  declarations: [
    AppComponent,
    LoginComponent,
    HeaderComponent,
    HomeComponent,
    UserManagementComponent,
    ActorComponent,
    FilmComponent,
    SeriesComponent,
    ProductComponent,
    SafeUrlPipe,
    FilmListComponent,
    HeroComponent,
    CoverComponent,
    SeasonComponent,
    ChapterComponent,
    SeriesListComponent,
    ],
  imports: [
    BrowserModule,
    FormsModule,
    HttpClientModule,
    RoutingModule,
    TokenModule,
    MaterialModule,
    NgbTimepickerModule,
    HttpInterceptorModule
  ],
  providers: [],
  bootstrap: [AppComponent],
})
export class AppModule {
}