public class PinInfo : ViewModelBase, INotifyLocationChanged
{
    private Location location;

    public event EventHandler<LocationChangedEventArgs> LocationChanged;

    public Location Location
    {
        get { return location; }
        set 
        {
            var oldLocation = this.location;
            this.location = value; 
            this.OnLocationChanged(oldLocation, this.location);
        }
    }

    public void OnLocationChanged(Location oldLocation, Location newLocation)
    {
        if (LocationChanged != null)
        {
            LocationChanged(this, new LocationChangedEventArgs(oldLocation, newLocation));
        }
    }
}