How to refresh list in xamarin form

Hello,

public class Product
{
public int ProductID { get; set; }
public string ProductName {get;set;}
public int Quantity { get; set; }
public double Price { get; set; }
}

List product=new List();

I am displaying a list of product and change the quantity of particular product. But it is not reflecting on screen. Is there any way to that using ViewModel approach?