如何在Angular 5中读取app.module中的appsettings文件？

{
  "apiEndpoint": "https://api.example.com",
  "apiKey": "your-api-key"
}

// environment.ts
export const environment = {
  production: false,
  appSettingsFile: 'appsettings.json'
};

// environment.prod.ts
export const environment = {
  production: true,
  appSettingsFile: 'appsettings.json'
};

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { environment } from '../environments/environment';

@Injectable({
  providedIn: 'root'
})
export class ConfigService {
  private appSettings: any;

  constructor(private http: HttpClient) { }

  loadAppSettings(): Promise<any> {
    return this.http.get(environment.appSettingsFile)
      .toPromise()
      .then((data: any) => {
        this.appSettings = data;
      });
  }

  getAppSetting(key: string): any {
    return this.appSettings[key];
  }
}

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { HttpClientModule } from '@angular/common/http';

import { AppComponent } from './app.component';
import { ConfigService } from './config.service';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    HttpClientModule
  ],
  providers: [
    ConfigService
  ],
  bootstrap: [AppComponent]
})
export class AppModule { }

import { Component, OnInit } from '@angular/core';
import { ConfigService } from './config.service';

@Component({
  selector: 'app-root',
  template: `
    <h1>App Settings</h1>
    <p>API Endpoint: {{ apiEndpoint }}</p>
    <p>API Key: {{ apiKey }}</p>
  `
})
export class AppComponent implements OnInit {
  apiEndpoint: string;
  apiKey: string;

  constructor(private configService: ConfigService) { }

  ngOnInit(): void {
    this.configService.loadAppSettings()
      .then(() => {
        this.apiEndpoint = this.configService.getAppSetting('apiEndpoint');
        this.apiKey = this.configService.getAppSetting('apiKey');
      });
  }
}