protected override async void OnNavigatedTo(NavigationEventArgs e)
{
var viewModel = new CarViewModel();
await viewModel.InitializeData();
this.DataContext = viewModel;
MapLayer layer = new MapLayer();
var pts = new List <GeoCoordinate>();
foreach (var item in viewModel.Cars)
{
Pushpin pushpin = new Pushpin();
pushpin.GeoCoordinate = new System.Device.Location.GeoCoordinate(item.latitude, item.longitude);
MapOverlay overlay = new MapOverlay();
overlay.Content = pushpin;
overlay.GeoCoordinate = new System.Device.Location.GeoCoordinate(item.latitude, item.longitude);
layer.Add(overlay);
pts.Add(new System.Device.Location.GeoCoordinate(item.latitude, item.longitude));
}
map.Layers.Clear();
map.Layers.Add(layer);
map.SetView(LocationRectangle.CreateBoundingRectangle(pts));
base.OnNavigatedTo(e);
}