Revit 2013: Where can I get the T wall joins?

Question

I'm trying to get all the joins from a given wall inside Revit, but all the resources I've found over the web are not working.

The LocationCurve.get_ElementsAtJoin(n) only returns a few, and as the documentation points out:

Get all elements joining to the end of this element's location

I also tried the ElementIntersectsSolidFilter as the SDK shows, but it's returning 0 intersections.

Answer 1

Try working in reverse and getting all the ends for the walls that join your main wall that match your element ID for the main wall.

Whilst this is a seemingly slow process you could do it once and store if it is an oft repeated situation.

The following code gives the gist, and am sure it could be improved (and is untested).

/// <summary>
/// Create a dictionary of adjoinging walls keyed on a particular wall ID.
/// </summary>
/// <param name="document">Tje Revit API Document</param>
/// <returns>A dictionary keyed on a wall id containing a collection of walls that adjoin the key id wall</returns>
public IDictionary<ElementId,ICollection<Wall>> GetAdjoiningWallsMap(Document document)
{
    IDictionary<ElementId, ICollection<Wall>> result = new Dictionary<ElementId, ICollection<Wall>>();

    FilteredElementCollector collector = new FilteredElementCollector(document);
    collector.OfClass(typeof(Wall));
    foreach (Wall wall in collector.Cast<Wall>())
    {
        IEnumerable<Element> joinedElements0 = GetAdjoiningElements(wall.Location as LocationCurve, wall.Id, 0);
        IEnumerable<Element> joinedElements1 = GetAdjoiningElements(wall.Location as LocationCurve, wall.Id, 1);
        result[wall.Id] = joinedElements0.Union(joinedElements1).OfType<Wall>().ToList();
    }
    return result;
}

private IEnumerable<Element> GetAdjoiningElements(LocationCurve locationCurve, ElementId wallId, Int32 index)
{
    IList<Element> result = new List<Element>();
    ElementArray a = locationCurve.get_ElementsAtJoin(index);
    foreach (Element element in a)
        if (element.Id != wallId)
            result.Add(element);
    return result;
}