IsolateParameter_1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.Threading.Tasks;
using Autodesk.Revit.DB;
using Autodesk.Revit.ApplicationServices;
using Autodesk.Revit.Attributes;
using Autodesk.Revit.UI;
using Autodesk.Revit.UI.Selection;
using System.Collections;

namespace IsolateParameter
{
    [Transaction(TransactionMode.Manual)]
    [Regeneration(RegenerationOption.Manual)]
    public class sop_IsolateParameter : IExternalCommand
    {
        public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
        {
            //Get application and documetn objects
            UIApplication uiapp = commandData.Application;
            UIDocument uidoc = uiapp.ActiveUIDocument;
            Document doc = uidoc.Document;
            Application app = uiapp.Application;


            using (Transaction t = new Transaction(doc, "sop_IsolateParameter"))
            {
                t.Start("sop_IsolateParameter");
                try
                {

                    View view = uidoc.ActiveView;

                    // all elements in active view
                    var collector = new FilteredElementCollector(doc, view.Id).WhereElementIsNotElementType();
                    List<Element> elementsInView = new List<Element>();

                    foreach (Element e in collector)
                    {
                        if (null != e.Category
                          && e.Category.HasMaterialQuantities)
                        {
                            elementsInView.Add(e);
                        }
                    }

                    //Create UserWindowControl 
                    UserWindControl userWindControl = new UserWindControl(elementsInView, view, uidoc);
                    userWindControl.Show();

                }


                catch (Autodesk.Revit.Exceptions.OperationCanceledException)
                {
                    return Result.Cancelled;
                }
                catch (Exception ex)
                {
                    message = ex.Message;
                    return Result.Failed;
                }


                t.Commit();

            }

            return Result.Succeeded;

        }
    }
}