angular4 http headers，如何设置？

Question

import { Injectable } from '@angular/core';
import { Http, Headers, Response, RequestOptions,  } from '@angular/http';
@Injectable()
export class RoleService {
    headers = new Headers({"Content-Type": "application/json"});
     options = new RequestOptions({ headers: this.headers });
     constructor(private http: Http) {  }

    getRoleList(data) {
         return this.http.post('http://192.168.10.178:9080/role/getRole', data, this.options)
                .toPromise()
                .then(res => res.json().data)
                .then(data => { return data; });
    }
}

/image/nPiK8.png

帮帮我!!怎么解决这个问题？？？

Answer 1

尝试

export class RoleService {
  options: RequestOptions;

  constructor(private http: Http) {
    let headers: any = new Headers();
    headers.append('Content-Type', 'application/json');

    this.options = new RequestOptions({ headers: headers });
  }

// ........