private void Toolbar_ItemEnabledChanged(MyToolbar toolbar, MyToolbar.SlotArgs args) { if (args.SlotNumber.HasValue) { var idx = args.SlotNumber.Value; m_toolbarItemsGrid.GetItemAt(idx).Enabled = toolbar.IsEnabled(toolbar.SlotToIndex(idx)); } else { for (int i = 0; i < m_toolbarItemsGrid.ColumnsCount; ++i) { m_toolbarItemsGrid.GetItemAt(i).Enabled = toolbar.IsEnabled(toolbar.SlotToIndex(i)); } } }