protected virtual void OnDropCheck(object sender, RoutedEventArgs e) { DropCheckEventArgs Args = (DropCheckEventArgs)e; IExtendedTreeNode DropDestinationItem = Args.DropDestinationItem as IExtendedTreeNode; if (DropDestinationItem != null && DropDestinationItem.Children.Count == 0 && TreeViewSettingsWindow.AreLeavesSealed) { Args.Deny(); } }
protected virtual void OnDropCheck(object sender, RoutedEventArgs e) { if (e == null) { throw new ArgumentNullException(nameof(e)); } DropCheckEventArgs Args = (DropCheckEventArgs)e; IExtendedTreeNode DropDestinationItem = (IExtendedTreeNode)Args.DropDestinationItem; if (DropDestinationItem != null && ((ICollection <IExtendedTreeNode>)DropDestinationItem.Children).Count == 0 && TreeViewSettingsWindow.AreLeavesSealed) { Args.Deny(); } }