这是我之前 帖子 的后续。我已经调试这个问题一段时间了，尽管我还没有修复它，但我发现了一些问题，所以也许有人能帮忙。

这是整个设置：
app-config.json (/src/assets/):

{
  "apiUrl": "localhost:8080"
}

app-config.service.ts (/src/app/):

import {Injectable, Injector} from '@angular/core';
import {HttpClient} from '@angular/common/http';

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

  private appConfig: any;

  constructor (private injector: Injector) { }

  loadAppConfig() {
    let http = this.injector.get(HttpClient);

    return http.get('/assets/app-config.json')
      .toPromise()
      .then(data => {
        this.appConfig = data;
      })
  }

  get config() {
    return this.appConfig;
  }

}

app.module.ts (/src/app/):

import {APP_INITIALIZER, NgModule} from '@angular/core';
import {HttpClientModule} from '@angular/common/http';
import {AppConfigService} from './app-config.service';
import {CometdService} from './cometd/cometd.service';

const appInitializerFn = (appConfig: AppConfigService) => {
  return () => {
    return appConfig.loadAppConfig();
  }
};

@NgModule({
...
  providers: [HttpClientModule,
    AppConfigService,
    {
      provide: APP_INITIALIZER,
      useFactory: appInitializerFn,
      multi: true,
      deps: [AppConfigService]
    }]
})

export class AppModule {
  constructor(cometdService: CometdService) {}
}

cometd.service.ts (/src/app/cometd/):

import {Injectable, OnDestroy} from '@angular/core';
import {Store} from '@ngrx/store';
import * as fromRoot from '../reducers';
import {AppConfigService} from '../app-config.service';

export interface CometDExtended extends cometlib.CometD {
  websocketEnabled: boolean;
}

@Injectable({
  providedIn: 'root'
})
export class CometdService implements OnDestroy {

  protected cometd: CometDExtended = new cometlib.CometD() as CometDExtended;

  private subscriptions: cometlib.SubscriptionHandle[] = [];

  constructor(private environment: AppConfigService, private store: Store<fromRoot.State>) {
    let config = environment.config;
    let apiUrl = environment.config.apiUrl;
    
    this.cometd.configure('http://localhost:8080/cometd');
    this.startConnection();
  }
...
}

• 这个问题发生在各种服务上。 CometD 只是一个例子。
• app-config.service.ts 中的数据本身已正确获取，即 loadAppConfig() 返回 { "apiUrl": "localhost:8080" }。
• 注入的环境 (AppConfigService) 已定义，即其类型为 Object。
• environment.config 未定义，因此 environment.config.apiUrl 返回错误：“TypeError：无法读取未定义的属性（读取‘apiUrl’）”。