private void RemoveTool(BaseToolLayer t)
{
if (t.MapControl == this)
{
t.MapControl = null;
}
_registeredTools.Remove(t);
t.PropertyChanged -= TOnPropertyChanged;
}
private void RegisterTool(BaseToolLayer t)
{
t.MapControl = this;
_registeredTools.Add(t);
t.PropertyChanged += TOnPropertyChanged;
}