public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
{
UIApplication uiapp = commandData.Application;
UIDocument uidoc = uiapp.ActiveUIDocument;
Application app = uiapp.Application;
Document doc = uidoc.Document;
XYZ p1 = new XYZ(0, 0, 0) / 304.8;
XYZ p2 = new XYZ(1000, 0, 0) / 304.8;
XYZ p3 = new XYZ(1000, 1000, 0) / 304.8;
IList <CurveLoop> ppp = new List <CurveLoop>();
CurveLoop lp = new CurveLoop();
Line line = Line.CreateBound(p1, p2);
Line line1 = Line.CreateBound(p2, p3);
Line line2 = Line.CreateBound(p3, p1);
lp.Append(line);
lp.Append(line1);
lp.Append(line2);
CurveLoop pp = CurveLoop.CreateViaOffset(lp, 500 / 304.8, XYZ.BasisZ);
ppp.Add(lp);
ppp.Add(pp);
CeilingType ct = new FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_Ceilings)
.OfClass(typeof(CeilingType)).FirstElement() as CeilingType;
using (Transaction trans = new Transaction(doc, "fe"))
{
trans.Start("fo");
Ceiling createcl = Ceiling.Create(doc, ppp, ct.Id, doc.ActiveView.GenLevel.Id);
trans.Commit();
}
return(Result.Succeeded);
}