如何通过Angular 5传递标头数据？

Question

这在Angular 4中有效。要使其在Angle 5中正常工作，我需要进行哪些更改？

 getGreeting(): Observable<string> {
    let headers = new Headers({ 'Authorization': 'Bearer ' + this.authenticationService.token });

  //cant find requestoptions
  let options = new RequestOptions({ headers: headers });

    return this.http.
        get(Constant.ApiRoot + Constant.GreetingService, options).
        map((response: Response) => response.text());
}

Answer 1

标头可以作为HttpHeaders或Plain JSON对象传递，但它应该是HttpOptions的一部分。您可以在Angular的官方文档中找到有关它的更多信息，网址为https://angular.io/guide/http#adding-headers

const httpOptions = {
      headers: new HttpHeaders({      
        'Authorization': Bearer ' + this.authenticationService.token 
      })
    };
this.httpClientObj.get('url',httpOptions);