无法读取未定义的属性“注释”

Question

我想使用ng2-translate。我看了this tutorial ..我做错了什么？

这是我的组件：

... 
import {TranslateService, TranslatePipe, TranslateLoader, TranslateStaticLoader} from 'ng2-translate/ng2-translate';
import {Http as ngHttp, HTTP_PROVIDERS } from '@angular/http';
import {Http} from '../shared/common/http'

 @Component({
    templateUrl: './app.html',
    pipes: [TranslatePipe]
 })

类别：

export class MyApp {

constructor(platform: Platform, 
  private menu: MenuController, 
  private taxFileService: TaxFileService, 
  private http: Http,
  private menuService: MenuService, 
  private accountService: AccountService, 
  private sessionService: SessionService,
  **private  translate: TranslateService**) 

Ionic bootstrap：

ionicBootstrap(MyApp, [[provide(TranslateLoader, {
  useFactory: (http: ngHttp) => new CustomLoader(),
  deps: [ngHttp]
}),
  TranslateService,StorageService, TaxFileService, MenuService, AccountService, Logger, SessionService, Http,HTTP_PROVIDERS]], {
}); 

我的CustomLoader：

class CustomLoader implements TranslateLoader {
    getTranslation(lang: string): Observable<any> {
        return Observable.of({"USER": "UserEng"});
    }
}

错误在哪里？