Update PolygonShapeFile manualy

Jan 6, 2015 at 12:34 PM
Hello ,
When i creating a shape file ,on creation i want to define a default Extent ,with specific coordinates,
when i doing this and then UpdateExtent() or save() method,
the extent back to you default values X[-180|180],Y[-90|90]

can someone explain how to do this right ?
thanx.
                List<Coordinate> vertices = new List<Coordinate>();

                vertices.Add(new Coordinate(34.9176563465214, 32.4394761554574, -0.002436160109937, 0));
                vertices.Add(new Coordinate(34.9176563465214, 32.4394761554574, -0.002436160109937, 0));
                vertices.Add(new Coordinate(34.9176563465214, 32.4394761554574, -0.002436160109937, 0));
                vertices.Add(new Coordinate(34.9176563465214, 32.4394761554574, -0.002436160109937, 0));
               
                Polygon geom = new Polygon(vertices);
                _FeatureSet.Extent = new Extent(geom.Envelope);
                _FeatureSet.UpdateExtent();