public class DashboardExtractDataSource :
    IDashboardDataSource,
    IDashboardComponent,
    IComponent,
    IDisposable,
    ISupportInitialize,
    ISupportPrefix,
    IDashboardDataSourceInternal,
    IDataComponent,
    IServiceContainer,
    IServiceProvider,
    ISensitiveInfoContainer,
    IFederationDataProvider,
    IFederationDataSchemaProvider

Public Class DashboardExtractDataSource
    Implements IDashboardDataSource,
               IDashboardComponent,
               IComponent,
               IDisposable,
               ISupportInitialize,
               ISupportPrefix,
               IDashboardDataSourceInternal,
               IDataComponent,
               IServiceContainer,
               IServiceProvider,
               ISensitiveInfoContainer,
               IFederationDataProvider,
               IFederationDataSchemaProvider

using DevExpress.DashboardCommon;
using DevExpress.DashboardWin;
using System.IO;
using System.Linq;
using System.Windows.Forms;

namespace ExtractDataSourceExample {
    public partial class Form1 : DevExpress.XtraEditors.XtraForm {
        public Form1() {
            InitializeComponent();
            dashboardViewer1.CustomizeDashboardTitle += DashboardViewer1_CustomizeDashboardTitle;
            dashboardViewer1.LoadDashboard("DashboardTest.xml");
        }

        delegate void SafeUpdate(string file);
        private void CreateExtractAndSave() {
            DataSourceCollection dsCollection = new DataSourceCollection();
            dsCollection.AddRange(dashboardViewer1.Dashboard.DataSources.Where(d => !(d is DashboardExtractDataSource)));
            foreach (var ds in dsCollection) {
                    DashboardExtractDataSource extractDataSource = new DashboardExtractDataSource();
                    extractDataSource.ExtractSourceOptions.DataSource = ds;

                    if (ds is DashboardSqlDataSource)
                        extractDataSource.ExtractSourceOptions.DataMember = ((DashboardSqlDataSource)(ds)).Queries[0].Name;

                    extractDataSource.FileName = Path.GetFullPath($"Extract_{ds.Name}.dat");
                    extractDataSource.UpdateExtractFile();
                    foreach (DataDashboardItem item in dashboardViewer1.Dashboard.Items)
                        if (item.DataSource == ds)
                            item.DataSource = extractDataSource;
            }
            dashboardViewer1.Dashboard.DataSources.RemoveRange(dsCollection);
            dashboardViewer1.Dashboard.SaveToXml("Dashboard_Extract.xml");
        }

        private void UpdateExtract() {
            dashboardViewer1.ReloadData();
            foreach (var ds in dashboardViewer1.Dashboard.DataSources.Where(d => d is DashboardExtractDataSource)) {
                ((DashboardExtractDataSource)ds).UpdateExtractFile();
            }
        }

        private async void UpdateExtractAsync() {
            await dashboardViewer1.UpdateExtractDataSourcesAsync(
                (fileName, result) => { 
                    OnDataReady(fileName); 
                },
                (fileName, result) => { 
                    MessageBox.Show($"File {fileName} updated "); 
                });
        }

        void OnDataReady(string fileName) {
            dashboardViewer1.Invoke(new SafeUpdate(UpdateViewer), new object[] { fileName });
        }
        void UpdateViewer(string fileName) {
            MessageBox.Show($"Data for the file {fileName} is ready ");
            dashboardViewer1.ReloadData();
        }

        private void DashboardViewer1_CustomizeDashboardTitle(object sender, CustomizeDashboardTitleEventArgs e) {
            DashboardToolbarItem itemUpdate = new DashboardToolbarItem((args) => UpdateExtract()) {
                Caption = "Update Extract Data Source",
            };
            e.Items.Add(itemUpdate);

            DashboardToolbarItem itemUpdateAsync = new DashboardToolbarItem((args) => UpdateExtractAsync()) {
                Caption = "Async Update Extract Data Sources",
            };
            e.Items.Add(itemUpdateAsync);

            DashboardToolbarItem itemSave = new DashboardToolbarItem((args) => CreateExtractAndSave()) {
                Caption = "Create Extract Data Source",
            };
            e.Items.Insert(0,itemSave);
        }
    }
}

Imports DevExpress.DashboardCommon
Imports DevExpress.DashboardWin
Imports System.IO
Imports System.Linq
Imports System.Windows.Forms

Namespace ExtractDataSourceExample
    Partial Public Class Form1
        Inherits DevExpress.XtraEditors.XtraForm

        Public Sub New()
            InitializeComponent()
            AddHandler dashboardViewer1.CustomizeDashboardTitle, AddressOf DashboardViewer1_CustomizeDashboardTitle
            dashboardViewer1.LoadDashboard("DashboardTest.xml")
        End Sub

        Private Delegate Sub SafeUpdate(ByVal file As String)
        Private Sub CreateExtractAndSave()
            Dim dsCollection As New DataSourceCollection()
            dsCollection.AddRange(dashboardViewer1.Dashboard.DataSources.Where(Function(d) Not (TypeOf d Is DashboardExtractDataSource)))
            For Each ds In dsCollection
                Dim extractDataSource As New DashboardExtractDataSource()
                extractDataSource.ExtractSourceOptions.DataSource = ds

                If TypeOf ds Is DashboardSqlDataSource Then
                    extractDataSource.ExtractSourceOptions.DataMember = DirectCast(ds, DashboardSqlDataSource).Queries(0).Name
                End If

                extractDataSource.FileName = Path.GetFullPath($"Extract_{ds.Name}.dat")
                extractDataSource.UpdateExtractFile()
                For Each item As DataDashboardItem In dashboardViewer1.Dashboard.Items
                    If item.DataSource Is ds Then
                        item.DataSource = extractDataSource
                    End If
                Next item
            Next ds
            dashboardViewer1.Dashboard.DataSources.RemoveRange(dsCollection)
            dashboardViewer1.Dashboard.SaveToXml("Dashboard_Extract.xml")
        End Sub

        Private Sub UpdateExtract()
            dashboardViewer1.ReloadData()
            For Each ds In dashboardViewer1.Dashboard.DataSources.Where(Function(d) TypeOf d Is DashboardExtractDataSource)
                CType(ds, DashboardExtractDataSource).UpdateExtractFile()
            Next ds
        End Sub

        Private Sub UpdateExtractAsync()
            dashboardViewer1.UpdateExtractDataSourcesAsync(
                Sub(fileName, result)
                    OnDataReady(fileName)
                End Sub,
                Sub(fileName, result)
                    MessageBox.Show($"File {fileName} updated ")
                End Sub)
        End Sub

        Private Sub OnDataReady(ByVal fileName As String)
            dashboardViewer1.Invoke(New SafeUpdate(AddressOf UpdateViewer), New Object() {fileName})
        End Sub
        Private Sub UpdateViewer(ByVal fileName As String)
            MessageBox.Show($"Data for the file {fileName} is ready ")
            dashboardViewer1.ReloadData()
        End Sub

        Private Sub DashboardViewer1_CustomizeDashboardTitle(ByVal sender As Object, ByVal e As CustomizeDashboardTitleEventArgs)
            Dim itemUpdate As New DashboardToolbarItem(Sub(args) UpdateExtract()) With {.Caption = "Update Extract Data Source"}
            e.Items.Add(itemUpdate)

            Dim itemUpdateAsync As New DashboardToolbarItem(Sub(args) UpdateExtractAsync()) With {.Caption = "Async Update Extract Data Sources"}
            e.Items.Add(itemUpdateAsync)

            Dim itemSave As New DashboardToolbarItem(Sub(args) CreateExtractAndSave()) With {.Caption = "Create Extract Data Source"}
            e.Items.Insert(0,itemSave)
        End Sub
    End Class
End Namespace

[WebMethod]
public static string UpdateExtractDataSource() {
    DashboardExtractDataSource ds = CreateExtractDataSource();
    StringBuilder sb = new StringBuilder("We updated your extract data source. ");
    var task = DashboardExtractDataSource.UpdateFile(ds,
        (fileName, result) => {
            sb.AppendLine($"{DateTime.Now.ToString("T")} - Data Updated - {result} - {Path.GetFileName(fileName)}. ");
        },
        (fileName, result) => {
            sb.AppendLine($"{DateTime.Now.ToString("T")} - File Updated - {result} - {Path.GetFileName(fileName)}. ");
        });
    // Wait until the data is refreshed in the Extract Data Source.
    task.Wait();
    return sb.ToString();
}

<WebMethod>
Public Shared Function UpdateExtractDataSource() As String
    Dim sb As StringBuilder = New StringBuilder("We updated your extract data source. ")
    Dim ds As DashboardExtractDataSource = CreateExtractDataSource()
    Dim task As Task = DashboardExtractDataSource.UpdateFile(
        ds,
        Sub(fileName, result)
            sb.AppendLine($"{DateTime.Now.ToString("T")} - Data Updated - {result} - {Path.GetFileName(fileName)}. ")
        End Sub,
        Sub(fileName, result)
            sb.AppendLine($"{DateTime.Now.ToString("T")} - File Updated - {result} - {Path.GetFileName(fileName)}. ")
        End Sub)
    ' Wait until the data is refreshed in the Extract Data Source.
    task.Wait()
    Return sb.ToString
End Function

function UpdateExtractDataSource() {
    $.ajax({
        url: "Default.aspx/UpdateExtractDataSource",
        type: "POST",
        data: {},
        contentType: "application/json; charset=utf-8"
    }).then(function (result) {
        dashboard.ReloadData();
        DevExpress.ui.notify(result.d, "success", 5000);
    }, function () {
        DevExpress.ui.notify("We could not update extract data source.", "error", 2000)
    });
}