How to use

NavController

in

ionic-angular

go(lat, long) {
  this.navCtrl.push(MapPage, {
   item: {
    lat: lat,
    long: long
   }
  });
 }

login ( ) : void
  {
    let payload =
    {
      userName    : this.username,
      password    : this.password
    };

    this._dataframeAccount.login ( payload ).then (

      ( value ) =>
      {
        this._app.getRootNav().setRoot(DashboardComponent);
      },
      ( error ) =>
      {
        console.log ( error );
      }

    );
  }

login() {
  let loading = this.loadingCtrl.create({
   content: "Please wait..."
  });
  loading.present();
  this.loginService.login(this.username, this.password).subscribe(
   data => {
    // this.statusBar.backgroundColorByHexString("#25312C")
    this.provider.token = data['token'];
    localStorage.setItem('token', this.provider.token);
    this.provider.userData = jwtDecode( data['token']);
    console.log(this.provider.userData)
    this.navCtrl.push(TabsPage);
    loading.dismiss();
   },
   error => {
    console.log(error)
    let alert = this.alertCtrl.create({
     title: "Alert!",
     subTitle: "OOOOPS... Something Went Wrong",
     buttons: ["Dismiss"]
    });
    loading.dismiss();
    alert.present();
   }
  );
 }

  this._app.getRootNav().setRoot(LoginComponent);
this._app.getRootNav().setRoot(LoginComponent);
this._app.getRootNav().setRoot(LoginComponent);

cancel() {
  this.navCtrl.pop();
 }

 loading.dismiss();
 alert.present();
 this.navCtrl.pop();
},
error => {
 loading.dismiss();
 alert.present();
 this.navCtrl.pop();
 console.log(error);

console.log("data", data);
loading.dismiss()
this.navCtrl.push(BookingPage, {
 item: data
});

cancel(){
  this.navCtrl.pop();
 }

signin() {
  this.navCtrl.pop();
 }

cancel() {
  this.navCtrl.pop();
 }

signup() {
  this.navCtrl.push(SignupPage);
 }

  this._app.getRootNav().setRoot(LoginComponent);
this._app.getRootNav().setRoot(LoginComponent);
this._app.getRootNav().setRoot(LoginComponent);

  this._app.getRootNav().setRoot(LoginComponent);
this._app.getRootNav().setRoot(LoginComponent);
this._app.getRootNav().setRoot(LoginComponent);

  this._app.getRootNav().setRoot(DashboardComponent);
this._app.getRootNav().setRoot(LoginComponent);
this._app.getRootNav().setRoot(LoginComponent);

  this._app.getRootNav().setRoot(LoginComponent);
this._app.getRootNav().setRoot(LoginComponent);
this._app.getRootNav().setRoot(LoginComponent);