如何在Angular2中设置默认HTTP头？

>选项#1：使用BaseRequestOptions类

您可以扩展此类,并将标题设置为用于每个请求：

@Injectable()
export class DefaultRequestOptions extends BaseRequestOptions{
    headers:Headers = new Headers({
        'Content-Type': 'application/x-www-form-urlencoded'
    });
}

并按如下所述进行注册：

bootstrap(AppComponent,[
    HTTP_PROVIDERS,provide( RequestOptions,{ useClass: DefaultRequestOptions })
});

>选项#2：扩展Http类本身

您还可以扩展Http类并设置所需的标题,如下所述：

@Injectable()
export class CustomHttp extends Http {
  constructor(backend: ConnectionBackend,defaultOptions: RequestOptions) {
    super(backend,defaultOptions);
  }

  request(url: string | Request,options?: RequestOptionsArgs): Observable<Response> {
    return super.request(url,options);        
  }

  get(url: string,options?: RequestOptionsArgs): Observable<Response> {
    // Add headers into options
    (...)
    return super.get(url,options);
  }

  (...)
}

并按如下所述进行注册：

bootstrap(AppComponent,[
  HTTP_PROVIDERS,provide(Http,{
    useFactory: (backend: XHRBackend,defaultOptions: RequestOptions) => new CustomHttp(backend,defaultOptions),deps: [XHRBackend,RequestOptions]
  })
]);

希望它能帮助你,蒂埃里