private Address _SelectedItemFrom;
        public Address SelectedItemFrom {
            get { return _SelectedItemFrom; }
            set
            {
                if (_SelectedItemFrom != value) {
                    _SelectedItemFrom = value;
                    RaisePropertyChanged();
                    getCoordinatesAsync("from");
                }
            }
        }


        private Address _SelectedItemTo;
        public Address SelectedItemTo {
            get { return _SelectedItemTo; }
            set
            {
                if (_SelectedItemTo != value) {
                    _SelectedItemTo = value;
                    RaisePropertyChanged();
                    getCoordinatesAsync("to");
                }
            }
        }

        public ICommand StartNavigation { get; set; }

        public MapNavigarionVM() {

            StartNavigation = new Command(async () => {

                await Navigate();
            });
        }
        private async void getCoordinatesAsync(string ToOrFrom) {

            try {
                if (ToOrFrom.Equals("to")) {
                    var address = $"{SelectedItemTo.street} , {SelectedItemTo.city} , {SelectedItemTo.state}";
                    var locations = await Geocoding.GetLocationsAsync(address);
                    var location = locations?.FirstOrDefault();
                    if (location != null) {
                        SelectedItemTo.Lat = location.Latitude;
                        SelectedItemTo.lon = location.Longitude;
                    }
                } else if (ToOrFrom.Equals("from")) {
                    var address = $"{SelectedItemFrom.street} , {SelectedItemFrom.city} , {SelectedItemFrom.state}";
                    var locations = await Geocoding.GetLocationsAsync(address);
                    var location = locations?.FirstOrDefault();
                    if (location != null) {
                        SelectedItemFrom.Lat = location.Latitude;
                        SelectedItemFrom.lon = location.Longitude;
                    }
                }
            } catch (Exception ex) {
                await Application.Current.MainPage.DisplayAlert("Error", ex.Message, "OK");
            }
        }

        public async Task Navigate() {
            var location = new Location(SelectedItemTo.lon, SelectedItemTo.Lat) ;
            var options = new MapLaunchOptions { NavigationMode = NavigationMode.Driving };

            await Map.OpenAsync(location, options);
        }