BuildingCoder.CmdCategories.Execute C# (CSharp) Метод

        public Result Execute(
            ExternalCommandData commandData,
            ref string message,
            ElementSet elements)
        {
            UIApplication uiapp = commandData.Application;
              Application app = uiapp.Application;
              Document doc = uiapp.ActiveUIDocument.Document;
              Categories categories = doc.Settings.Categories;

              int nCategories = categories.Size;

              Debug.Print(
            "{0} categories and their parents obtained "
            + "from the Categories collection:",
            nCategories );

              foreach( Category c in categories )
              {
            Category p = c.Parent;

            Debug.Print( "  {0} ({1}), parent {2}",
              c.Name, c.Id.IntegerValue,
              ( null == p ? "<none>" : p.Name ) );
              }

              Array bics = Enum.GetValues(
            typeof( BuiltInCategory ) );

              int nBics = bics.Length;

              Debug.Print( "{0} built-in categories and the "
            + "corresponding document ones:", nBics );

              Category cat;
              string s;

              List<BuiltInCategory> bics_null
            = new List<BuiltInCategory>();

              List<BuiltInCategory> bics_exception
            = new List<BuiltInCategory>();

              foreach( BuiltInCategory bic in bics )
              {
            try
            {
              cat = categories.get_Item( bic );

              if( null == cat )
              {
            bics_null.Add( bic );
            s = "<null>";
              }
              else
              {
            s = string.Format( "{0} ({1})",
              cat.Name, cat.Id.IntegerValue );
              }
            }
            catch( Exception ex )
            {
              bics_exception.Add( bic );

              s = ex.GetType().Name + " " + ex.Message;
            }
            Debug.Print( "  {0} --> {1}",
              bic.ToString(), s );
              }

              int nBicsNull = bics_null.Count;
              int nBicsException = bics_exception.Count;

            #if ACCESS_HIDDEN_CATEGORIES_THROUGH_FILTERED_ELEMENT_COLLECTOR
              // Trying to use OfClass( typeof( Category ) )
              // throws an ArgumentException exception saying
              // "Input type Category is not a recognized
              // Revit API type".

              IEnumerable<Category> cats
            = new FilteredElementCollector( doc )
              .WhereElementIsNotElementType()
              .WhereElementIsViewIndependent()
              .Cast<Category>();

              // Unable to cast object of type
              // 'Autodesk.Revit.DB.Element' to type
              // 'Autodesk.Revit.DB.Category':

              int nCategoriesFiltered = cats.Count<Category>();

              Debug.Print(
            "{0} categories obtained from a filtered "
            + "element collector:",
            nCategoriesFiltered );

              foreach( Category c in cats )
              {
            Debug.Print( "  {0}", c.Name );
              }
            #endif // ACCESS_HIDDEN_CATEGORIES_THROUGH_FILTERED_ELEMENT_COLLECTOR

              TaskDialog dlg = new TaskDialog(
            "Hidden Built-in Categories" );

              s = string.Format(
            "{0} categories obtained from the Categories collection;\r\n"
            + "{1} built-in categories;\r\n"
            + "{2} built-in categories retrieve null result;\r\n"
            + "{3} built-in categories throw an exception:\r\n",
            nCategories, nBics, nBicsNull, nBicsException );

              Debug.Print( s );

              dlg.MainInstruction = s;

              s = bics_exception
            .Aggregate<BuiltInCategory, string>(
              string.Empty,
              ( a, bic ) => a + "\n" + bic.ToString() );

              Debug.Print( s );

              dlg.MainContent = s;

              dlg.Show();

              return Result.Succeeded;
        }