public static IPolygon GeneratePolygon(IGeometry pl)
{
if (pl.IsEmpty || (pl is IPolyline) == false)
{
return(null);
}
var pc1 = (IPointCollection)pl;
var pg = new PolygonClass();
var pc2 = (IPointCollection)pg;
for (var i = 0; i < pc1.PointCount; i++)
{
var pt = pc1.get_Point(i);
var pt2 = new PointClass {
X = pt.X, Y = pt.Y
};
pc2.AddPoint(pt2);
}
var pt3 = pc1.get_Point(0);
var pt4 = new PointClass {
X = pt3.X, Y = pt3.Y
};
pc2.AddPoint(pt4);
pg.Simplify();
return(pg);
}