void AddItem(object sender, EventArgs e) { IViewItem _viewItem = new ItemForm(); _viewItem.ItemCreated += delegate(RadioComponent rc) { int maxKey = Items.Keys.Count() != 0 ? Items.Keys.Max() : 0; try { _manager.AddNode(rc, _view.SelectedCategoryName, ++maxKey); Items.Add(maxKey, rc); _view.UpdateItems(Items); } catch (Exception ex) { _messageService.ShowError(ex.Message); } }; _viewItem.Show(); }