public RedlineEditingCtrl(IMapViewer viewer, RedlineLayer layer)
: this()
{
_viewer = viewer;
_layer = layer;
_viewer.PropertyChanged += OnViewerPropertyChanged;
_ed = new RedlineEditor(_viewer, _layer);
this.Disposed += OnDisposed;
lblRedlineLayerName.Text = _layer.Name;
_origToolbarColor = btnRefresh.BackColor;
}