4、三種方法 從Revit選取元素

①先選取、再執行

public Result SelectElements(ExternalCommandData commandData)
        {
            UIDocument uidoc = commandData.Application.ActiveUIDocument;
            Document doc = uidoc.Document;

            Selection selection = uidoc.Selection;
            ICollection<ElementId> set = selection.GetElementIds();
            if(set.Count <= 0)
            {
                TaskDialog.Show("Revit","你沒有選中任何元素！");return Result.Failed;
            }
            else
            {
                string str = "所選元素類型為：";
                foreach (ElementId ele in set)
                {
                    Element selectelement = doc.GetElement(ele);
                    str +="\n\t"+ selectelement.GetType().ToString();

                }
                TaskDialog.Show("Revit", str);
            }

            return Result.Succeeded;
        }