public class PieDashboardItem :
    ChartDashboardItemBase,
    IPieContext,
    IElementContainer

Public Class PieDashboardItem
    Inherits ChartDashboardItemBase
    Implements IPieContext,
               IElementContainer

using DevExpress.DashboardCommon;
using System;
using System.Windows.Forms;

namespace Dashboard_CreatePies
{
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }
        private PieDashboardItem CreatePies(IDashboardDataSource dataSource) {
            PieDashboardItem pies = new PieDashboardItem();
            pies.DataSource = dataSource;
            pies.Values.Add(new Measure("Extended Price"));
            pies.Arguments.Add(new Dimension("Country"));
            pies.SeriesDimensions.Add(new Dimension("OrderDate"));
            return pies;
        }
        private void Form1_Load(object sender, EventArgs e) {
           DashboardExcelDataSource excelDataSource = new DashboardExcelDataSource()
            {
                FileName = "SalesPerson.xlsx",
                SourceOptions = new DevExpress.DataAccess.Excel.ExcelSourceOptions(
                    new DevExpress.DataAccess.Excel.ExcelWorksheetSettings()
                    {
                        WorksheetName = "Data",
                        CellRange = "A1:L100"
                    }
                )
            };
            excelDataSource.Fill();

            Dashboard dashBoard = new Dashboard();
            dashBoard.DataSources.Add(excelDataSource);
            PieDashboardItem pies = CreatePies(excelDataSource);
            dashBoard.Items.Add(pies);

            dashboardViewer1.Dashboard = dashBoard;
            dashboardViewer1.ReloadData();
        }
    }
}

Imports DevExpress.DashboardCommon
Imports System
Imports System.Windows.Forms

Namespace Dashboard_CreatePies
    Partial Public Class Form1
        Inherits Form

        Public Sub New()
            InitializeComponent()
        End Sub
        Private Function CreatePies(ByVal dataSource As IDashboardDataSource) As PieDashboardItem
            Dim pies As New PieDashboardItem()
            pies.DataSource = dataSource
            pies.Values.Add(New Measure("Extended Price"))
            pies.Arguments.Add(New Dimension("Country"))
            pies.SeriesDimensions.Add(New Dimension("OrderDate"))
            Return pies
        End Function
        Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
            Dim excelDataSource As New DashboardExcelDataSource()
            excelDataSource.FileName = "SalesPerson.xlsx"
            Dim options As New DevExpress.DataAccess.Excel.ExcelSourceOptions()
            Dim importSettings = New DevExpress.DataAccess.Excel.ExcelWorksheetSettings()
            importSettings.WorksheetName = "Data"
            importSettings.CellRange = "A1:L100"
            options.ImportSettings = importSettings
            excelDataSource.SourceOptions = options
            excelDataSource.Fill()

            Dim dashBoard As New Dashboard()
            dashBoard.DataSources.Add(excelDataSource)
            Dim pies As PieDashboardItem = CreatePies(excelDataSource)
            dashBoard.Items.Add(pies)

            dashboardViewer1.Dashboard = dashBoard
            dashboardViewer1.ReloadData()
        End Sub
    End Class
End Namespace