角度4+。在解析器处理过程中显示微调器

Question

在解析程序执行某些工作时，是否可以显示微调框而不是空白页？

我有一个带有两个解析器的模块：

 const routes: Routes = [
  {
    path: '',
    component: MyComponent,
    canActivate: [MyAuthGuard],
    resolve: {
      vehicles: FirstResolve,
      drivers: SecondResolve
    },
    children: [
      {
        path: '',
        component: FirstComponent
      },

      {
        path: ':id',
        component: SecondComponent
      }
    ]
  }
];

每个解析程序都会执行一些耗时的操作，例如对服务器的请求：

@Injectable()
export class FirstResolve implements Resolve<Entity[]>{

  constructor(
    private _firstService: FirstService,
    private _secondService: SecondService,
    private _store: Store<any>
  ) { }

  async resolve(): Promise<Entity[]> {
    let data = await Promise.all([
      this._firstService.getEntities(),
      this._secondService.getEntities()
    ]);

    this._store.dispatch(...);
    this._store.dispatch(...);

    return;
  }

}

您能帮我弄清楚吗？