public static bool TryGetUserString(this GeometryBase geometry, string key, out Autodesk.Revit.DB.ElementId value, Autodesk.Revit.DB.ElementId def) { if (geometry.TryGetUserString(key, out int id, def.IntegerValue)) { value = new Autodesk.Revit.DB.ElementId(id); return(true); } value = def; return(false); }