Angular在用户登录后设置授权请求头headers.append('Authorization', 'token');

方案1. 使用Angular  http

import {Injectable} from '@angular/core';
import {Http, Headers} from '@angular/http';

@Injectable()
export class HttpClient {

  constructor(private http: Http) {}

  createAuthorizationHeader(headers: Headers) {
    headers.append('Authorization', 'Basic ' +
      btoa('username:password')); 
  }

  get(url) {
    let headers = new Headers();
    this.createAuthorizationHeader(headers);
    return this.http.get(url, {
      headers: headers
    });
  }

  post(url, data) {
    let headers = new Headers();
    this.createAuthorizationHeader(headers);
    return this.http.post(url, data, {
      headers: headers
    });
  }
}

方案2.Angular 4.3.x及更高版本可以执行如下操作来添加请求头

2.1拦截器设置

import {
  HttpEvent,
  HttpInterceptor,
  HttpHandler,
  HttpRequest,
} from '@angular/common/http';

export class AddHeaderInterceptor implements HttpInterceptor {
  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    // Clone the request to add the new header
    const clonedRequest = req.clone({ headers: req.headers.set('Authorization', 'Bearer 123') });

    // Pass the cloned request instead of the original request to the next handle
    return next.handle(clonedRequest);
  }
}

2.2创建拦截器后，您应该使用HTTP_INTERCEPTORS提供的注册。

import { HTTP_INTERCEPTORS } from '@angular/common/http';

@NgModule({
  providers: [{
    provide: HTTP_INTERCEPTORS,
    useClass: AddHeaderInterceptor,
    multi: true,
  }],
})
export class AppModule {}

方案3.配置扩展BaseRequestOptions

3.1配置代码如下

import {provide} from 'angular2/core';
import {bootstrap} from 'angular2/platform/browser';
import {HTTP_PROVIDERS, Headers, Http, BaseRequestOptions} from 'angular2/http';

import {AppCmp} from './components/app/app';


class MyRequestOptions extends BaseRequestOptions {
  constructor () {
    super();
    this.headers.append('My-Custom-Header','MyCustomHeaderValue');
  }
} 

bootstrap(AppCmp, [
  ROUTER_PROVIDERS,
  HTTP_PROVIDERS,
  provide(RequestOptions, { useClass: MyRequestOptions })
]);

3.2添加请求头

this.http._defaultOptions.headers.append('Authorization', 'token');
或者
this.http._defaultOptions.headers.set('Authorization', 'token');

3.3删除请求头

this.http._defaultOptions.headers.delete('Authorization');

参考来源：https://www.itranslater.com/qa/details/2112366855208829952