ionic2使用根导航（rootNav）跳转

在一个使用tab构建的ionic2应用程序中，如果我们直接使用NavController进行导航跳转，会将新的page压入当前tab的导航栈中。但login、signin、setting等page在业务上不应该属于当前tab，而应该从根组件进行导航，那么此时该如何做呢？
看下面的例子即可：

在一个组件中跳转到根导航中

import { Component } from '@angular/core';
import { App, ViewController } from 'ionic-angular';

@Component({
    template: `
    <ion-content>
      <h1>My PopoverPage</h1>
      <button ion-button (click)="pushPage()">Call pushPage</button>
     </ion-content>
    `
  })
  class PopoverPage {
    constructor(
      public viewCtrl: ViewController
      public appCtrl: App
    ) {}

    pushPage() {
      this.viewCtrl.dismiss();
      this.appCtrl.getRootNav().push(SecondPage);
    }
  }

在主组件中跳转到一个根导航

import { Component, ViewChild } from '@angular/core';
import { NavController } from 'ionic-angular';

@Component({
   template: '<ion-nav #myNav [root]="rootPage"></ion-nav>'
})
export class MyApp {
   @ViewChild('myNav') nav: NavController
   public rootPage = TabsPage;

   // Wait for the components in MyApp's template to be initialized
   // In this case, we are waiting for the Nav with reference variable of "#myNav"
   ngOnInit() {
      // Let's navigate from TabsPage to Page1
      this.nav.push(Page1);
   }
}

---

end 2017-02-08 11:32:08
参考文档： http://ionicframework.com/docs/v2/api/navigation/NavController/