我想在打开时保留单选按钮的值，并使用modalcontroller关闭Ionic2中的模态

Question

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


import { FormGroup, FormControl} from '@angular/forms';
import { ViewController} from 'ionic-angular';
import { ModalController } from 'ionic-angular';
import { TabsPage } from "../tabs/tabs"
@IonicPage()
@Component({
  selector: 'page-dashboard',
  templateUrl: 'listing.html'
})

export class ListingPage {

  constructor(public navCtrl: NavController, public navParams: NavParams, public modalCtrl: ModalController) {

  }

  ionViewDidLoad() {
    console.log('ionViewDidLoad Dashboard');
  }
  //modals started
  filterSort() {

     let modal = this.modalCtrl.create(SortModal);
    modal.present();
  }

}
@Component({
  selector:"sort-page",
  templateUrl:"filter/sort.listing.filter.html",
  providers:[ListingPage]
})
export class SortModal {
  relationship:string;
  filtersStore:Array<string>=[];
  public myForm: FormGroup;

  constructor(private _filterservice:FilterModalsService,private _v:ViewController,private _sharedservice: SharedService,private listingpage:ListingPage,public navCtrl: NavController){
        this.myForm = new FormGroup({
        langs: new FormControl()
      })

  }
   doSubmit() {
    this.listingpage.onSearch(0,true);
    this._v.dismiss();
  }

   reset(){
    this.myForm.reset();
    this._sharedservice.deleteData();
  }
}

listingpage是父组件，我在其中打开SortModal组件作为离子2中的模态，子项为SortModal但是当我通过defualt打开模态时，每个元素都被重置然后我从列表中选择一个并关闭模态，但当我再次打开模态时，所有值再次为空。我希望保留值，我之前选择的无线电元素