How to count all Element in that are similar to the FilteredElementCollector Symbol family of Special Equipment?

Question

When I use DesignAutomation (Autodesk Forge) to count the number of BuiltInCategory.OST_SpecialityEquiosystem elements visible on the Revit file by getting the FilteredElementCollector lstEleCollector = new FilteredElementCollector (doc, doc.ActiveView.Id); .But I realized that there is no Active View concept in Design Automation. So is there a way to count all the elements that appear in the rvt file?

Answer 1

To count all elements of a given category in a document you should use FilteredElementCollector.OfCategory():

FilteredElementCollector collector = new FilteredElementCollector(doc);
ICollection<Element> collection = collector.OfCategory(BuiltInCategory.OST_SpecialityEquiosystem)
    .ToElements();
int count = collection.Count;

This will however give you all elements in the document. To find elements in a given view, you will need to know the view id. If you do not know the view id, you can iterate through all views in a document and find the view you are looking for.

FilteredElementCollector collector = new FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_Views);
foreach (Autodesk.Revit.DB.View v in collector.ToElements())
{
    if (v && v.Name == "My Special View")
        viewId = v.Id;
}

Then you can call the API you already know with this viewId instead of doc.ActiveView.Id.

FilteredElementCollector lstEleCollector = new FilteredElementCollector (doc, viewId);
ICollection<Element> collection = lstEleCollector.OfCategory(BuiltInCategory.OST_SpecialityEquiosystem)
    .ToElements();
int count = collection.Count;

Also refer our very basic forge-countdeletewalls-revit code sample which does something similar to what you are attempting. It counts walls, doors, floors and windows in a given document.