public static void LoadPolygonList(string fileName)
{
ShapeManager.Remove <Polygon>(
mShapeCollection.Polygons);
PolygonSaveList polygonSaveList = PolygonSaveList.FromFile(fileName);
mShapeCollection.Polygons.AddRange(
polygonSaveList.ToPolygonList());
ShapeManager.AddPolygonList(mShapeCollection.Polygons);
LastLoadedFile = fileName;
}