public MainWindowModel()
{
var marker1 = new Marker(1);
var marker2 = new Marker(2);
var marker3 = new Marker(3);
Markers = new ObservableCollection<Marker>
{
marker1,
marker2,
marker3
};
}
public void AddMarker()
{
var id = Markers.Any() ? Markers.Max(x => x.Id) + 1 : 1;
var marker = new Marker(id);
Markers.Add(marker);
}