How to Edit Pop-up Window Font of FlexGrid Column Filtering Menu

When setting the Column Header of the FlexGrid control to bold, all the contents within the pop-up window for sorting/filtering the column also appear bold.

<c1:FlexGrid ColumnHeaderFontWeight="Bold"/>

To control the appearance of the text within the pop-up window, you will need to handle the GridColumn's FilterLoading and OptionsLoading events as follows:

private void Col_OptionsLoading(object? sender, C1.WPF.Grid.GridColumnOptionsLoadingEventArgs e)
{
    e.Menu.FontWeight = FontWeights.Normal;
}

private void Col_FilterLoading(object? sender, C1.WPF.Grid.GridColumnFilterLoadingEventArgs e)
{
    e.DataFilter.FontWeight = FontWeights.Normal;
}

These properties can be edited as needed to produce the desired formatting results.