Implementing Multi-Category Tags in Revit

Method to implement Multi-Category Tags in Revit

1. Keyword for Tag method: IndependentTag

2. There are two methods for creating tags. The input parameters are basically the same, but there are some differences. The following description and image can help distinguish them better.

   First function: Creates a multi-category tag using an actual project coordinate point without needing to specify the tag type.
   Create Method (Document, ElementId, ElementId, Reference, Boolean, TagOrientation, XYZ)

   Second function: Controls the display position via UVPoint, i.e., a point on the element, and requires specifying the tag category.
   Create( Document document, ElementId ownerDBViewId, Reference referenceToTag, bool addLeader, TagMode tagMode, TagOrientation tagOrientation, XYZ pnt )


3. Code example: Reads elements in the view via document and places multi-category annotations. If multi-view simultaneous operation is needed, you need to find all views and pass them in to get all elements.

using (Transaction transaction= new Transaction(doc))
           {
               transaction.Start("TT");
               
               
               var collector = new FilteredElementCollector(doc);
               var views = collector.OfClass(typeof(View)).OfCategory(BuiltInCategory.OST_Views).Cast<View>().Where(v=>
                   (v.ViewType == ViewType.EngineeringPlan || v.ViewType == ViewType.FloorPlan) && v.CanBePrinted); 
               foreach (var view in views)
               {
                   var instances = new FilteredElementCollector(doc, view.Id).WhereElementIsNotElementType()
                       .Where(x => x.GetType() == typeof(FamilyInstance) || x.GetType() == typeof(Pipe))
                       .ToList();

                   foreach (Element instance in instances)
                   {
                       var reference = new Reference(instance);
                   
                       IndependentTag.Create(doc,view.Id,reference,true,TagMode.TM_ADDBY_MULTICATEGORY,TagOrientation.Vertical,XYZ.Zero);
                       
                       IndependentTag.Create(doc,new ElementId(7315142) ,view.Id,reference,true,TagOrientation.Vertical,XYZ.Zero);
                   }
               
               }
               
               transaction.Commit();
           }