问Angular6 -使用API调用加载使用ngx到后端的转换

EN

export function httpLoaderFactory(http: HttpClient) {
  return new TranslateHttpLoader(http, "http://localhost:xxxx/api/translation/", "");
}

TranslateModule.forRoot({
  loader: {
    provide: TranslateLoader,
    useFactory: httpLoaderFactory,
    deps: [HttpClient]
  }
}),

In Module :

export class CustomLoader implements TranslateLoader {

  constructor(private http: Http) {}

  public getTranslation(lang: String): Observable<any> {
    return this.http.get(URL).map(
      (res: any) => {
        return res;
      }
    );

  }
}

@NgModule({
  imports: [
    TranslateModule.forRoot({
      provide: TranslateLoader,
      useClass: CustomLoader,
      // useFactory: (createTranslateLoader),
      deps: [Http]
    })
  ]
}) 

 constructor(private _translate: TranslateService){}

 const transText = this._translate.instant('something');