public Task<PivotDrillDownDataSource> CreateDrillDownDataSourceAsync()

Public Function CreateDrillDownDataSourceAsync As Task(Of PivotDrillDownDataSource)

using DevExpress.Xpf.Core;
using DevExpress.Xpf.PivotGrid;
using System.Collections.ObjectModel;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;

namespace WpfDrillDownDataSourceExample {
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>

    public partial class MainWindow : ThemedWindow {
        public ObservableCollection<MyOrderRow> OrderSourceList { get; set; }
        public ObservableCollection<MyOrderRow> OrderDrillDownList { get; set; }
        public MainWindow() {
            InitializeComponent();
            OrderSourceList = DatabaseHelper.CreateData();
            pivotGridControl1.DataSource = OrderSourceList;
        }
        private async void PivotGridControl1_CellSelectionChanged(object sender, RoutedEventArgs e) {
            OrderDrillDownList = new ObservableCollection<MyOrderRow>();
            var selectionCopy = 
                pivotGridControl1.MultiSelection.SelectedCells.Cast().ToList();
            foreach (var cellPoint in selectionCopy) {
                foreach (PivotDrillDownDataRow record in 
                         await pivotGridControl1.CreateDrillDownDataSourceAsync(cellPoint.X, cellPoint.Y)) {

                    OrderDrillDownList.Add(OrderSourceList[record.ListSourceRowIndex]);
                }
            }
            gridControl1.ItemsSource = OrderDrillDownList;
        }
        private void ThemedWindow_Loaded(object sender, RoutedEventArgs e) {
            pivotGridControl1.BestFitArea = DevExpress.Xpf.PivotGrid.FieldBestFitArea.FieldHeader;
            pivotGridControl1.BestFit();
        }

        private async void pivotGridControl1_CellClick(object sender, PivotCellEventArgs e) {
            gridControl1.ItemsSource = 
                await pivotGridControl1.CreateDrillDownDataSourceAsync(e.ColumnIndex, e.RowIndex);
        }
    }
}

Imports DevExpress.Xpf.Core
Imports DevExpress.Xpf.PivotGrid
Imports System.Collections.ObjectModel
Imports System.Linq
Imports System.Windows

Namespace WpfDrillDownDataSourceExample

    ''' <summary>
    ''' Interaction logic for MainWindow.xaml
    ''' </summary>
    ''' 
    Public Partial Class MainWindow
        Inherits ThemedWindow

        Public Property OrderSourceList As ObservableCollection(Of MyOrderRow)

        Public Property OrderDrillDownList As ObservableCollection(Of MyOrderRow)

        Public Sub New()
            Me.InitializeComponent()
            OrderSourceList = CreateData()
            Me.pivotGridControl1.DataSource = OrderSourceList
        End Sub

        Private Async Sub PivotGridControl1_CellSelectionChanged(ByVal sender As Object, ByVal e As RoutedEventArgs)
            OrderDrillDownList = New ObservableCollection(Of MyOrderRow)()
            Dim selectionCopy = pivotGridControl1.MultiSelection.SelectedCells.Cast(Of System.Drawing.Point)().ToList()
            For Each cellPoint In selectionCopy
                For Each record As PivotDrillDownDataRow In Await pivotGridControl1.CreateDrillDownDataSourceAsync(cellPoint.X, cellPoint.Y)

                    OrderDrillDownList.Add(OrderSourceList(record.ListSourceRowIndex))
                Next record
            Next cellPoint
            gridControl1.ItemsSource = OrderDrillDownList
        End Sub

        Private Sub ThemedWindow_Loaded(ByVal sender As Object, ByVal e As RoutedEventArgs)
            Me.pivotGridControl1.BestFitArea = FieldBestFitArea.FieldHeader
            Me.pivotGridControl1.BestFit()
        End Sub
        Private Async Sub pivotGridControl1_CellClick(ByVal sender As Object, ByVal e As PivotCellEventArgs)
            gridControl1.ItemsSource = Await pivotGridControl1.CreateDrillDownDataSourceAsync(e.ColumnIndex, e.RowIndex)
        End Sub

    End Class

<dx:ThemedWindow
    x:Class="WpfDrillDownDataSourceExample.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
    xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid"
    xmlns:dxpg="http://schemas.devexpress.com/winfx/2008/xaml/pivotgrid"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    Width="800"
    Height="600"
    mc:Ignorable="d"
    Loaded="ThemedWindow_Loaded"
    Title="Create Drill-Down Data Source Example">

    <Grid>
    <!-- ... -->
        <dxpg:PivotGridControl
            x:Name="pivotGridControl1"
            Grid.Row="0"
            Grid.ColumnSpan="2"
            UseAsyncMode="true"
            CellClick="pivotGridControl1_CellClick"
            CellSelectionChanged="PivotGridControl1_CellSelectionChanged"
            DataProcessingEngine="Optimized">
            <!-- ... -->
        </dxpg:PivotGridControl>
        <!-- ... -->
    </Grid>

</dx:ThemedWindow>