问如何在ionic 3上创建scrollTop按钮

EN

import { Component, ViewChild } from '@angular/core';
import { IonicPage, NavController, NavParams, ToastController, Content } 
from 'ionic-angular';
import { AngularFireAuth } from "angularfire2/auth";
import { MenuController } from "ionic-angular";
import { PrediosPage } from '../predios/predios';


@IonicPage()
@Component({
  selector: 'page-home',
  templateUrl: 'home.html',
})
export class HomePage {

  @ViewChild('pageTop') pageTop: Content;

  public pageScroller(){
    this.pageTop.scrollToTop();
  }

  searchQuery: string = '';
  items: any[];

  constructor(private afAuth: AngularFireAuth, private toast: 
  ToastController,
  public navCtrl: NavController, public navParams: NavParams, public menu: 
  MenuController) {

      this.initializeItems();

  }

<ion-content #pageTop>

<div paddign>

<ion-searchbar (ionInput)="getItems($event)" placeholder="Pesquisar"> 
</ion-searchbar>

<ion-list>
<ion-item *ngFor="let item of items" (click)="itemTapped($event, item)">
  <ion-thumbnail item-left>
     <img [src]="item.imagem">
  </ion-thumbnail>
  <h2 style="color:#886AEA">{{ item?.nome }}</h2>
   <p>Rua: {{ item?.rua }} - {{ item?.numero }}</p>
   </ion-item>
</ion-list>

</div>


<ion-fab right bottom>
  <button ion-fab color="darkroyal" (click)="pageTop"><ion-icon name="ios-arrow-up"></ion-icon></button>
</ion-fab>