Hi,

I'm using the following approach for adding field chooser context menus for column headers:

public class ExtendedGrid : XamDataGrid, IColumnLayout
{
    protected override void OnFieldLayoutInitialized(FieldLayoutInitializedEventArgs args)
    {
        base.OnFieldLayoutInitialized(args);

        this.SetupColumnMenus();

        foreach (FieldLayout colLayout in this.FieldLayouts)
        {
            colLayout.Fields.CollectionChanged += this.OnFieldsChanged;
        }
    }

    private void OnFieldsChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        this.SetupColumnMenus();
    }

    private void SetupColumnMenus()
    {
        Style originalStyle = this.FindResource(typeof(LabelPresenter)) as Style;

        foreach (FieldLayout colLayout in this.FieldLayouts)
        {
            ContextMenu columnSubMenu = new ContextMenu();

            Style headerPresenterStyle = new Style(typeof(DataRecordPresenter));
            Trigger isHeaderRecordTrigger = new Trigger { Property = DataRecordPresenter.IsHeaderRecordProperty, Value = true };
            headerPresenterStyle.Triggers.Add(isHeaderRecordTrigger);
            isHeaderRecordTrigger.Setters.Add(new Setter(ContextMenuProperty, columnSubMenu));
            colLayout.Settings.DataRecordPresenterStyle = headerPresenterStyle;

            Style newSubStyle = new Style(typeof(LabelPresenter));
            newSubStyle.BasedOn = originalStyle;
            newSubStyle.Setters.Add(new Setter(ContextMenuProperty, columnSubMenu));

            foreach (Field col in colLayout.Fields.OrderBy(x => x.Label))
            {
                SetupColumnContextMenu(newSubStyle, columnSubMenu, col);
            }
        }
    }

    private static void SetupColumnContextMenu(Style styleWithContextMenu, ItemsControl columnMenu, Field col)
    {
        if (col == null || col.Settings == null)
        {
            return;
        }

        if (!col.HasLabel)
        {
            return;
        }

        col.Settings.LabelPresenterStyle = styleWithContextMenu;

        MenuItem item = new MenuItem() { Header = col.Label };            
        item.IsChecked = col.Visibility == Visibility.Visible;
        BindingOperations.SetBinding(col, Field.VisibilityProperty, new Binding() { Source = item, Path = new PropertyPath(MenuItem.IsCheckedProperty), Converter = new BooleanToVisibilityConverter(), Mode = BindingMode.OneWay });
        item.IsCheckable = true;
        columnMenu.Items.Add(item);
    }
}

This approch works nicely, however, one issue surfaced and I don't know why. Sometimes, the context menu just stops working. When you right click a column header, nothing happens. It starts working again if you expand a collapsed record and make OnFieldLayoutInitialized() fire again when a child field layout is loaded. So it seems to me that the grid loses track of the DataRecordPresenterStyle and LabelPresenterStyle. But for what reason? Is there some kind "recycling" / container generation of header controls taking place that causes such issues? Or anything else I am missing?

Regards,

Florian