The below code snippet shows how to delete all named boundaries from the DGN with their related sheets and drawings .

 public void DeleteAllNamedBoundaries()
        {

            List<string> nbList = new List<string>();

            //Get active DGN
            DgnModelRef dgnModelRef = Session.Instance.GetActiveDgnModelRef();
            DgnFile dgnFile = dgnModelRef.GetDgnFile();

            //Get all models 
            ModelIndexCollection modelIndexCollection = dgnFile.GetModelIndexCollection();
            foreach (ModelIndex modelIndex in modelIndexCollection)
            {
                DgnModel dgnModel = dgnFile.LoadRootModelById(out StatusInt status, modelIndex.Id);

                if (dgnModel.ModelType == DgnModelType.Normal)
                {
                    //Get Named Boundary Collection using DgnModel
                    NamedBoundaryCollection namedBoundaries = new NamedBoundaryCollection(dgnModel);
                    IEnumerator<NamedBoundary> namedBoundaryIterator = namedBoundaries.GetEnumerator();

                    //Add unique names of Named boundaries into list 
                    while (namedBoundaryIterator.MoveNext())
                    {
                        nbList.Add(namedBoundaryIterator.Current.UniqueName);
                    }
                }
            }

            //Iterate the names to delete named boundaries 
            foreach (string namedBoundaryName in nbList)
            {
                DeleteNamedBoundaryWithSheetAndDrawing(namedBoundaryName);
            }
        }

        public void DeleteNamedBoundaryWithSheetAndDrawing(string namedBoundaryUniqueName)
        {

            try
            {
                if (namedBoundaryUniqueName == null) return;

                //Get active DGN
                DgnModelRef dgnModelRef = Session.Instance.GetActiveDgnModelRef();
                DgnFile dgnFile = dgnModelRef.GetDgnFile();

                //Get all models 
                ModelIndexCollection modelIndexCollection = dgnFile.GetModelIndexCollection();
                foreach (ModelIndex modelIndex in modelIndexCollection)
                {
                    DgnModel dgnModel = dgnFile.LoadRootModelById(out StatusInt status, modelIndex.Id);

                    if (dgnModel.ModelType == DgnModelType.Normal)
                    {
                        //Get Named Boundary Collection using DgnModel
                        NamedBoundaryCollection namedBoundaries = new NamedBoundaryCollection(dgnModel);
                        if (namedBoundaries.Count() == 0) return;

                        //Get the named boundary from collection
                        var namedBoundaryToDelete = namedBoundaries.FirstOrDefault(m => m.UniqueName == namedBoundaryUniqueName);
                        if (namedBoundaryToDelete == null) return;

                        //Delete Named Boundary
                        namedBoundaryToDelete.Delete();
                        break;
                    }
                }


                //Generate sheet model and drawing model name from Named boundary unique name
                string drawingModelName = namedBoundaryUniqueName.Split(':').First() + " - " + namedBoundaryUniqueName.Split(':').Last();
                string sheetModelName = drawingModelName + " [Sheet]";

                //Iterate for deleting the sheet and drawing model
                foreach (ModelIndex modelIndex in modelIndexCollection)
                {
                    DgnModel dgnModel = dgnFile.LoadRootModelById(out StatusInt status, modelIndex.Id);

                    if (dgnModel.ModelType == DgnModelType.Sheet || dgnModel.ModelType == DgnModelType.Drawing)
                    {
                        //Delete models related to named boundary               
                        if (dgnModel.ModelName == drawingModelName || dgnModel.ModelName == sheetModelName)
                        {
                            //delete model
                            dgnFile.DeleteModel(dgnModel);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                Trace.WriteLine(ex.Message);
            }
        }

Copy to clipboard