Ionic3 изменить данные страницы с помощью `радио`

Когда я нажимаю «1 means» означает «январь», я хочу, чтобы ion-grid отображал данные добровольцев за январь. console.info уже получил правильные данные, но ion-grid не обновляется.

Это логин в веб-браузере

html-страница

<ion-header>
    <ion-toolbar color = "danger">
      <ion-buttons>
        <button ion-button navPop icon-only>
          <ion-icon ios = "ios-arrow-back" md = "md-arrow-back"></ion-icon>
        </button>
      </ion-buttons>
      <ion-buttons style = "background: transparent;" end> 
        <button style = "background: transparent;" (click) = "doRadio()">月份选择</button>
      </ion-buttons>
        <ion-title text-wrap>志愿者评选</ion-title>
    </ion-toolbar>
</ion-header>

<ion-content>

  <ion-grid>
    <ion-row>
      <ion-col>
        <ion-card (click) = "goToVolunteerVoteDetail(volunteer)" style = "width:26%" class = "pin" *ngFor = "let volunteers of volunteer">
          <img src = "{{volunteers.Preview_image1}}" height = "100">
          <div *ngIf = "volunteers.title" class = "volunteer-title">
            <small>{{volunteers.title}}</small>
          </div>
          <div class = "volunteer-title">{{volunteers.like_number}}分</div> <!-- 志愿者评选头像像素：505x505px -->
        </ion-card>
      </ion-col>
    </ion-row>
  </ion-grid>
</ion-content>

страница ts

import { Component } from '@angular/core';
import { NavController, NavParams, ToastController, AlertController, ModalController } from 'ionic-angular';
import { NewsDataProvider } from '../../providers/news-data/news-data';
import { VolunteerVoteDetailPage } from '../volunteer-vote-detail/volunteer-vote-detail';


@Component({
  selector: 'page-volunteer-vote',
  templateUrl: 'volunteer-vote.html',
})
export class VolunteerVotePage {
  volunteer:any;
  volunteer1:any;
  //volunteer2:any;
  // testRadioOpen = false;
  // testRadioResult: any;

  constructor(
    public navCtrl: NavController, public navParams: NavParams,
    public newsData:NewsDataProvider,public toastCtrl: ToastController,
    public alertCtrl: AlertController,public modalCtrl: ModalController
  ){
    this.getVolunteerVote();
    this.getVolunteerVote1();
    //this.getVolunteerVote2();
  }

  getVolunteerVote(): Promise<any> {
    return this.newsData.getVolunteerVote().then(data => {
      this.volunteer = data;
    });
  }
  getVolunteerVote1(): Promise<any> {
    return this.newsData.getVolunteerVote1().then(data => {
      this.volunteer1 = data;
    });
  }
  // getVolunteerVote2(): Promise<any> {
  //   return this.newsData.getVolunteerVote2().then(data => {
  //     this.volunteer2 = data;
  //   });
  // }

  goToVolunteerVoteDetail(volunteerItem:any) {
    this.navCtrl.push(VolunteerVoteDetailPage,{
      volunteer:volunteerItem
    });
  }

  doRadio() {
    const alert = this.alertCtrl.create();
    alert.setTitle('请选择月份');

    alert.addInput({
      type: 'radio',
      label: '1月',
      value: this.volunteer1,
      checked: true
    });

    // alert.addInput({
    //   type: 'radio',
    //   label: '2月',
    //   value: this.volunteer2
    // });

    alert.addButton({
      text: '确认',
      handler: (data: any) => {
        console.info('Radio data:', data);
        // this.testRadioOpen = false;
        // this.testRadioResult = data;
      }
    });
    alert.addButton('取消');

    alert.present();
  }


}

страница провайдера

getVolunteerVote() {
    return new Promise(resolve => {
      this.http.get('http').map(res => res.json().data).subscribe(data => {
          this.data = data;
          resolve(this.data);
        });
    });
  }
  getVolunteerVote1() {
    return new Promise(resolve => {
      this.http.get('http').map(res => res.json().data).subscribe(data => {
          this.data = data;
          resolve(this.data);
        });
    });
  }