扩展http类并访问自定义属性(Angular2 typescript)

import { Http } from '@angular/http';

export class CustomHttp extends Http {
  public customProperty: string;
}

import { Injectable } from '@angular/core';
import { Http, RequestOptions, ConnectionBackend, RequestOptionsArgs, Response, Headers } from '@angular/http';
import { CustomHttp } from './custom-http';

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

  request(url: string | Request, options?: RequestOptionsArgs): Observable<Response> {
    if (options instanceof RequestOptions) {
      let customHttp = new CustomHttp(this._backend, this._defaultOptions);
      customHttp.customProperty = "Custom Property Value";
      options = customHttp.merge(options);
    }
    return super.request(url, options);
  }
}

import { NgModule } from '@angular/core';
import { HttpModule, Http } from '@angular/http';
import { CustomHttpService } from './custom-http.service';

@NgModule({
  imports: [HttpModule],
  providers: [
    { provide: Http, useClass: CustomHttpService }
  ]
})
export class AppModule { }

import { Component } from '@angular/core';
import { Http } from '@angular/http';

@Component({
  selector: 'app-root',
  template: `
    <button (click)="getData()">Get Data</button>
  `
})
export class AppComponent {
  constructor(private http: Http) { }

  getData() {
    this.http.get('https://api.example.com/data')
      .subscribe(response => {
        let customProperty = response.customProperty;
        console.log(customProperty);
      });
  }
}