public MapPageCS()
        {
            CustomMap customMap = new CustomMap
            {
                MapType = MapType.Street
            };

            CustomPin pin = new CustomPin
            {
                Type     = PinType.Place,
                Position = new Position(37.79752, -122.40183),
                Label    = "Xamarin San Francisco Office",
                Address  = "394 Pacific Ave, San Francisco CA",
                Name     = "Xamarin",
                Url      = "http://xamarin.com/about/"
            };

            customMap.CustomPins = new List <CustomPin> {
                pin
            };
            customMap.Pins.Add(pin);
            customMap.MoveToRegion(MapSpan.FromCenterAndRadius(new Position(37.79752, -122.40183), Distance.FromMiles(1.0)));

            Content = customMap;
        }
        private async void OnButton(object sender, EventArgs e)
        {
            CustomPin pin = new CustomPin
            {
                Type     = PinType.SavedPin,
                Position = new Position(Convert.ToDouble(szerokosc.Text), Convert.ToDouble(dlugosc.Text)),
                Label    = nazwaEntry.Text,
                Address  = opisEntry.Text,
                Name     = "Xamarin",
                Url      = "http://xamarin.com/about/"
            };

            pin.MarkerClicked += async(s, args) =>
            {
                args.HideInfoWindow = true;
                string pinName = ((Pin)s).Label;
                string pytanie = ((Pin)s).Address;
                await DisplayAlert("Pin Clicked", $"{pinName} was clicked.", "Ok");

                string result = await DisplayPromptAsync("Zagadka", $"{pytanie}", initialValue : "10", maxLength : 2, keyboard : Keyboard.Numeric);
            };

            customMap.CustomPins = new List <CustomPin> {
                pin
            };
            customMap.Pins.Add(pin);



            var json = JsonConvert.SerializeObject(new { X = pin.Position.Latitude, Y = pin.Position.Longitude });

            var content = new StringContent(json, Encoding.UTF8, "application/json");

            HttpClient client = new HttpClient();

            var result = await client.PostAsync("http://dearjean.ddns.net:44201/api/Points", content);

            if (result.StatusCode == HttpStatusCode.Created)
            {
                await DisplayAlert("Komunikat", "Dodanie puntku przebiegło pomyślnie", "Anuluj");
            }
        }