MyContentPage.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Xamarin.Forms;

namespace ListViewDemoVS
{
    class MyContentPage : ContentPage
    {
        public MyContentPage()
        {
            Padding = new Thickness(0, Device.OnPlatform(20, 0, 0), 0, 0);

            List<Group> itemsGrouped = new List<Group>
            {
                new Group("Important", new List<ListItem>
                {
                    new ListItem { Title = "First", Description = "1st", Source="one.jpg", Price="$100" },
                    new ListItem { Title = "Second", Description = "2nd", Source="two.jpg", Price="$200" }
                }),
                new Group("Less Important", new List<ListItem>
                {
                    new ListItem { Title = "Third", Description = "3rd", Source="three.jpg", Price="$300" }
                })
            };

            ListView listView = new ListView()
            {
                IsGroupingEnabled = true,
                GroupDisplayBinding = new Binding("Key"),
                ItemTemplate = new DataTemplate(typeof(TextCell))
                {
                    Bindings =
                    {
                        { TextCell.TextProperty, new Binding("Title") },
                        { TextCell.DetailProperty, new Binding("Description") }
                    }
                },
                GroupHeaderTemplate = new DataTemplate(typeof(HeaderCell)),
                HasUnevenRows = true
            };
            listView.ItemsSource = itemsGrouped;

            /*
                listView.ItemsSource = new ListItem[] {
                    new ListItem { Title = "First", Description = "1st", Source="one.jpg", Price="$100" },
                    new ListItem { Title = "Second", Description = "2nd", Source="two.jpg", Price="$200" },
                    new ListItem { Title = "Third", Description = "3rd", Source="three.jpg", Price="$300" }
                };
                listView.RowHeight = 80;
                listView.BackgroundColor = Color.Black;
                listView.ItemTemplate = new DataTemplate(typeof(ListItemCell));
            */

            this.Content = listView;
        }
    }
}