How to use ion-scroll with virtualscroll and item-sliding

Ionic Framework ionic-v3
1

I am using virtualscroll for a long list but i want to see a scroll where i have to put ion-scroll tag

 <ion-list [virtualScroll]="contac" approxItemHeight="40px" bufferRatio="5">
   
    <ion-item><ion-label>Hepsini Seç</ion-label><ion-checkbox color="dark" (ionChange)="checkall()"></ion-checkbox></ion-item>
    <ion-item *virtualItem="let iten">
   <ion-label>{{iten.displayName}}</ion-label>
   <ion-checkbox color="dark" [checked]=check (ionChange)="addtodata(iten)"></ion-checkbox>
   

    </ion-item>
   
  </ion-list>

And More what about item-sliding


<ion-item-sliding *ngFor="let item of contac|sorting">
        
    <ion-item (press)="pressEvent($event)" >
    
    <ion-label >{{item}}</ion-label>
     <ion-checkbox *ngIf=control [checked]=checktool [@moveit]="state" color="dark" (ionChange)="addtodata(item)"></ion-checkbox>
  
     </ion-item>
      <ion-item-options side="left">
      <button ion-button color="secondary" (click)="config(item)" >
        <ion-icon name="cog"></ion-icon>
        Düzenle
      </button>
    </ion-item-options>
    </ion-item-sliding>

This is Css file

  ion-scroll {
  white-space: nowrap !important;
  height: 100% !important;
}