Angular中的核心模块，共享模块和功能模块之间的交互

Question

我具有以下文件夹结构，

Root Module (Apps)
Core Module (Library)
 -- ApiService
Shared Module (Library)
 -- Ui-Components
Feature Module (Library)
 -- ProductCatalog

我已将ApiService导入AppModule / rootModule

app.module.ts

@NgModule({
  declarations: [AppComponent],
  imports: [BrowserModule, CoreModule.forRoot()],
  providers: [],
  bootstrap: [AppComponent]
})

这是核心模块的实现

import {
  NgModule,
  Optional,
  SkipSelf,
  ModuleWithProviders
} from '@angular/core';
import { CommonModule } from '@angular/common';
import { AsyncService } from './async.service';

export function throwIfAlreadyLoaded(parentModule: any, moduleName: string) {
  if (parentModule) {
    const msg = `${moduleName} has already been loaded. Import Core modules in the AppModule only.`;
    throw new Error(msg);
  }
}
@NgModule({
  imports: [CommonModule]
})
export class CoreModule {
  constructor(@Optional() @SkipSelf() parentModule: CoreModule) {
    throwIfAlreadyLoaded(parentModule, 'CoreModule');
  }

  static forRoot(): ModuleWithProviders {
    return {
      ngModule: CoreModule,
      providers: [AsyncService]
    };
  }
}

API服务实现

import { Injectable } from '@angular/core';
import { CoreModule } from '@demo9/core';

@Injectable({
  providedIn: 'root'
})
export class AsyncService {
  constructor() {}

  getData() {
    const data = [
      {
        Id: 1,
        name: 'data1'
      },
      {
        Id: 2,
        name: 'data2'
      }
    ];
    return data;
  }
}

现在，想知道我们如何在功能特定服务中访问ApiService服务。我有点困惑。请提出建议。