在使用Ionic 2中的拦截器获取状态401时导航到登录页面

import { Injectable } from '@angular/core';
import { HttpInterceptor, HttpRequest, HttpHandler, HttpEvent } from '@angular/common/http';
import { Observable } from 'rxjs/Observable';
import { NavController } from 'ionic-angular';

@Injectable()
export class AuthInterceptor implements HttpInterceptor {
  constructor(private navCtrl: NavController) {}

  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(request).do(event => {}, error => {
      if (error.status === 401) {
        // 导航到登录页面
        this.navCtrl.setRoot(LoginPage);
      }
    });
  }
}

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { HttpClientModule, HTTP_INTERCEPTORS } from '@angular/common/http';
import { IonicModule, IonicApp, IonicErrorHandler } from 'ionic-angular';

import { MyApp } from './app.component';
import { AuthInterceptor } from './auth.interceptor';

@NgModule({
  declarations: [
    MyApp
  ],
  imports: [
    BrowserModule,
    HttpClientModule,
    IonicModule.forRoot(MyApp)
  ],
  bootstrap: [IonicApp],
  entryComponents: [
    MyApp
  ],
  providers: [
    { provide: HTTP_INTERCEPTORS, useClass: AuthInterceptor, multi: true },
    { provide: ErrorHandler, useClass: IonicErrorHandler }
  ]
})
export class AppModule {}