How can I flip a section using the Revit 2017 API

[Anonymous]

I have a section that I want to flip using the Revit API just like doing it with the UI as seen below.  I've tried using the ElementTransformUtils.MirrorElement but that only creates a copy with a duplicate view.

Here is a copy of my question on StackOverflow:

http://stackoverflow.com/questions/42164282/how-can-i-flip-a-live-section-with-the-revit-api

[FAIR59 · Accepted solution]

you can use another method from the ElementTransformUtils  (Revit 2017).

ElementTransformUtils.MirrorElements(document, sel , _plane, false);

with the 2nd argument a list of ElementId's

with the 4th argument set to false, meaning  no copies should be created and the elements should be mirrored directly.

[Anonymous]

mirroring only works if you set the flag to true - it only creates new elements and does nothing if boolean is set to false. Ideas? 

[FAIR59]

In my test, i selected the section  in a plan view and mirrored that section. That works fine.

So you will have to find the section  (Element of BuiltinCategory.OST_Viewers) of your view .

[FAIR59]

Here is my testcode

            Document document = revit.Application.ActiveUIDocument.Document;
            Autodesk.Revit.DB.View _view2mirror = document.ActiveView;
            List<Element> _sections = new FilteredElementCollector(document)
            .OfCategory(BuiltInCategory.OST_Viewers)
            .ToList();
            Element _section = null;
            foreach (Element _e in _sections)
            {
                if (_e.Name == _view2mirror.Name && _e.GetTypeId() == _view2mirror.GetTypeId()) _section = _e;
            }
            try
            {

                if( _section !=null)
            {
                using (Transaction t = new Transaction(document, "MirrorSection"))
                {
                    t.Start();
                    Plane _plane = Plane.CreateByNormalAndOrigin(_view2mirror.ViewDirection, _view2mirror.Origin);
                    ElementTransformUtils.MirrorElements(document, new List<ElementId> { _section.Id }, _plane, false);
                    t.Commit();
                }
            }
            return Result.Succeeded;
            }
            catch (Exception ex)
            {
                return Result.Failed;
            }

[Anonymous]

Thanks FAIR59.  This worked for me in Revit 2017.  I didn't even think about trying the plural MirrorElements because I was just wanting to mirror one at a time and I assumed that it had the same function signature (other than single element vs. collection of elements) as the singular MirrorElement.  It seems odd to me that they excluded the mirrorCopies parameter from the singular version of the function.

[Anonymous]

ksobon, are you using Revit 2017 or an older version?