protected override void OnDisposed()
{
// 스냅라인 등록 해제
Storyboard?.GuideLayer.Remove(this);
// GroupSelector
this.RemoveSelectedHandler(OnSelected);
this.RemoveUnselectedHandler(OnUnselected);
// Design Mode
DesignModeProperty.RemoveValueChanged(this, DesignMode_Changed);
// Grip Layer
AdornedElement.RemoveAdorner(GripLayer);
}