ArcMapAddinCoordinateConversion.DockableWindowCoordinateConversion.ArcMap_NewOpenDocument C# (CSharp) Method

        private void ArcMap_NewOpenDocument()
        {
            if(avEvents != null)
            {
                avEvents.SelectionChanged -= OnSelectionChanged;
                avEvents = null;
            }
            avEvents = ArcMap.Document.ActiveView as IActiveViewEvents_Event;
            avEvents.SelectionChanged += OnSelectionChanged;
        }