void FillNavBar(List <PivotGridField> hiddenFields)
    {
        NavBarGroup group0 = ASPxNavBar1.Groups[0];

        group0.Items.Clear();
        for (int i = 0; i < hiddenFields.Count; i++)
        {
            PivotGridField field = hiddenFields[i];
            NavBarItem     item  = group0.Items.Add(field.ToString());
            item.DataItem = field;
        }
        group0.ItemTextTemplate = new NavBarItemTemplate(ASPxPivotGrid1);
        group0.Expanded         = true;
    }
    public void InstantiateIn(Control container)
    {
        NavBarItemTemplateContainer c = (NavBarItemTemplateContainer)container;
        PivotGridField field          = (PivotGridField)c.Item.DataItem;

        if (field == null)
        {
            return;
        }
        Table        table  = new Table();
        ScriptHelper helper = new ScriptHelper(pivotGrid);

        table.ID           = helper.GetHeaderID(pivotGrid.Data.GetFieldItem(field));
        table.ClientIDMode = ClientIDMode.AutoID;
        table.Attributes.Add("onmousedown", helper.GetHeaderMouseDown());
        TableRow row = new TableRow();

        table.Rows.Add(row);
        TableCell cell = new TableCell();

        row.Cells.Add(cell);
        cell.Text = field.ToString();
        c.Controls.Add(table);
    }