How to set style for the Filter Row dropdown in WPF DataGrid (SfDataGrid)?

About the sample

This example illustrates how to set style for the Filter Row dropdown in WPF DataGrid (SfDataGrid).

WPF DataGrid (SfDataGrid) doesn’t have direct support to set style for the filter row dropdown. However, you can achieve this by creating custom GridFilterRowCell and RowGenerator.

public MainWindow()
 {
     InitializeComponent();
     this.dataGrid.RowGenerator = new CustomRowGenerator(this.dataGrid);
 }

public class GridFilterRowCellExt : GridFilterRowCell
{

    public GridFilterRowCellExt()
        : base()
    { }

    /// <summary>
    /// Opens the FilterOptionPopup with the FilterOptionList.
    /// </summary>

    public override void OpenFilterOptionPopup()
    {
        base.OpenFilterOptionPopup();

        var styleListBox = new Style(typeof(ListBox));

        styleListBox.Setters.Add(new Setter
        {
            Property = BackgroundProperty,
            Value = Brushes.Black
        });

        styleListBox.Setters.Add(new Setter
        {
            Property = ForegroundProperty,
            Value = Brushes.White
        });

        this.FilterOptionsList.Style = styleListBox;
        
    }
}

public class CustomRowGenerator : RowGenerator
{
    public CustomRowGenerator(SfDataGrid dataGrid)
        : base(dataGrid)
    {
    }

    /// <summary>
    /// Return the Custom FilterRowCell
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <returns>GridCell</returns>

    protected override GridCell GetGridCell<T>()
    {

        //If the Cell is FilterRowCell return custom FilterRowCell

        if (typeof(T) == typeof(GridFilterRowCell))
            return new GridFilterRowCellExt();
        return base.GetGridCell<GridCell>();
    }
}

Requirements to run the demo

Visual Studio 2015 and above versions.