Microsoft.Windows.Controls.Ribbon.RibbonMenuButton.OnPopupResizeStarted C# (CSharp) Метод

        void OnPopupResizeStarted(object sender, DragStartedEventArgs e)
        {
            RibbonDropDownHelper.OnPopupResizeStarted(_itemsPresenter);

            // Clear selection and close submenus when resizing.
            if (CurrentSelection != null)
            {
                RibbonMenuItem selectedMenuItem = CurrentSelection as RibbonMenuItem;
                CurrentSelection = null;
                if (selectedMenuItem != null)
                {
                    selectedMenuItem.IsSubmenuOpen = false;
                }
            }
            e.Handled = true;
        }