public static IPoint XY2JYD(ISpatialReference aSR, IPoint pXY)
        {
            IPoint point = new ESRI.ArcGIS.Geometry.Point();

            point = (pXY as IClone).Clone() as IPoint;
            if (aSR == null)
            {
                return(point);
            }
            if (aSR.Name != "Unknown")
            {
                point.SpatialReference = aSR;
                point.SnapToSpatialReference();
                if (aSR is IProjectedCoordinateSystem)
                {
                    IGeographicCoordinateSystem system = (aSR as IProjectedCoordinateSystem).GeographicCoordinateSystem;
                    point.Project(system);
                }
                return(point);
            }
            return(null);
        }