PointListPage

using System;
using System.Collections.Generic;
using Xamarin.Forms;
using Xamarin.Forms.Maps;

namespace MapDemoPage
{
    public partial class PointListPage : ContentPage
    {
        class GeoObject
        {
            public string name { get; set; }
            public double latitude;
            public double longitude;
            public GeoObject(string s, double lat, double lon)
            {
                name = s; latitude = lat; longitude = lon;
            }
        }
        Map map = new Map();
        public PointListPage()
        {
            Label header = new Label
            {
                Text = "Map Demo Page",
                FontAttributes = FontAttributes.Bold,
                HorizontalOptions = LayoutOptions.Center
            };
            Picker picker = new Picker
            {
                Title = "Select a Point",
                ItemsSource = new List<GeoObject> {
                    new GeoObject("Moscow", 55.755814, 37.617635),
                    new GeoObject("Saint-Petersburg", 59.939095, 30.315868),
                    new GeoObject("Sochi", 43.585525, 39.723062),
                    new GeoObject("Velikiy Novgorod", 58.52131, 31.271),
                    new GeoObject("Vladimir", 56.13655, 40.39658)
                }
            };
            picker.ItemDisplayBinding = new Binding("name");
            picker.SelectedIndexChanged += Picker_SelectedIndexChanged;
            // Build the page.
            Title = "Map Demo Page";
            Content = new StackLayout
            {
                Children =
{
header,
picker,
map
},
                Padding = new Thickness(0, 20, 0, 0)
            };
        }
        //обработка выбора объекта в списке
        private void Picker_SelectedIndexChanged(object sender, EventArgs e)
        {
            var picker = (Picker)sender;
            int selectedIndex = picker.SelectedIndex;
            if (selectedIndex != -1)
            {
                var geoObject = (GeoObject)picker.ItemsSource[selectedIndex];
                Position position = new Position(geoObject.latitude,
                geoObject.longitude);
                map.MoveToRegion(new MapSpan(position, 0.01, 0.01));
                var pin = new Pin
                {
                    Label = geoObject.name,
                    Position = position
                };
                pin.Clicked += Pin_Clicked;
                map.Pins.Add(pin);
            }
            if (selectedIndex != 0 & selectedIndex != 1 & selectedIndex != 2 & selectedIndex != 4)
            {
                DisplayAlert("Velikiy Novgorod", $" Население 224 297 чел.",
                "OK");
            }
            if (selectedIndex != 0 & selectedIndex != 1 & selectedIndex != 2 & selectedIndex != 3)
            {
                DisplayAlert("Vladimir", $" Население 357 907 чел.",
                "OK");
            }
        }
        //обработка нажатия на карте
        private async void Pin_Clicked(object sender, EventArgs e)
        {
            var selectedItem = (Pin)sender;
            if (selectedItem != null)
                await DisplayAlert("Tapped!", $"{selectedItem.Label} was tapped!",
                "OK");
        }
    }
}