using DevExpress.XtraSpreadsheet;
using DevExpress.XtraSpreadsheet.Commands;
using DevExpress.XtraSpreadsheet.Services;
using DevExpress.XtraSpreadsheet.Menu;
        private void spreadsheetControl1_PopupMenuShowing(object sender, PopupMenuShowingEventArgs e)
        {
            if (e.MenuType == SpreadsheetMenuType.Cell)
            {
                // Remove the "Clear Contents" menu item.
                e.Menu.RemoveMenuItem(SpreadsheetCommandId.FormatClearContentsContextMenuItem);

                // Disable the "Hyperlink" menu item.
                e.Menu.DisableMenuItem(SpreadsheetCommandId.InsertHyperlinkContextMenuItem);

                // Create a menu item for the Spreadsheet command, which inserts a picture into a worksheet.
                ISpreadsheetCommandFactoryService service = (ISpreadsheetCommandFactoryService)spreadsheetControl1.GetService(typeof(ISpreadsheetCommandFactoryService));
                SpreadsheetCommand cmd = service.CreateCommand(SpreadsheetCommandId.InsertPicture);
                SpreadsheetMenuItemCommandWinAdapter menuItemCommandAdapter = new SpreadsheetMenuItemCommandWinAdapter(cmd);
                SpreadsheetMenuItem menuItem = (SpreadsheetMenuItem)menuItemCommandAdapter.CreateMenuItem(DevExpress.Utils.Menu.DXMenuItemPriority.Normal);
                menuItem.BeginGroup = true;
                e.Menu.Items.Add(menuItem);

                // Insert a new item into the Spreadsheet popup menu and handle its click event.
                SpreadsheetMenuItem myItem = new SpreadsheetMenuItem("My Menu Item", new EventHandler(MyClickHandler));
                e.Menu.Items.Add(myItem);
            }
        }

        public void MyClickHandler(object sender, EventArgs e)
        {
            MessageBox.Show("My Menu Item Clicked!");
        }

Imports DevExpress.XtraSpreadsheet
Imports DevExpress.XtraSpreadsheet.Commands
Imports DevExpress.XtraSpreadsheet.Services
Imports DevExpress.XtraSpreadsheet.Menu
        Private Sub spreadsheetControl1_PopupMenuShowing(ByVal sender As Object, ByVal e As PopupMenuShowingEventArgs) Handles spreadsheetControl1.PopupMenuShowing
            If e.MenuType = SpreadsheetMenuType.Cell Then
                ' Remove the "Clear Contents" menu item.
                e.Menu.RemoveMenuItem(SpreadsheetCommandId.FormatClearContentsContextMenuItem)

                ' Disable the "Hyperlink" menu item.
                e.Menu.DisableMenuItem(SpreadsheetCommandId.InsertHyperlinkContextMenuItem)

                ' Create a menu item for the Spreadsheet command, which inserts a picture into a worksheet.
                Dim service As ISpreadsheetCommandFactoryService = CType(spreadsheetControl1.GetService(GetType(ISpreadsheetCommandFactoryService)), ISpreadsheetCommandFactoryService)
                Dim cmd As SpreadsheetCommand = service.CreateCommand(SpreadsheetCommandId.InsertPicture)
                Dim menuItemCommandAdapter As New SpreadsheetMenuItemCommandWinAdapter(cmd)
                Dim menuItem As SpreadsheetMenuItem = CType(menuItemCommandAdapter.CreateMenuItem(DevExpress.Utils.Menu.DXMenuItemPriority.High), SpreadsheetMenuItem)
                menuItem.BeginGroup = True
                e.Menu.Items.Add(menuItem)

                ' Insert a new item into the Spreadsheet popup menu and handle its click event.
                Dim myItem As New SpreadsheetMenuItem("My Menu Item", New EventHandler(AddressOf MyClickHandler))
                e.Menu.Items.Add(myItem)
            End If
        End Sub

        Public Sub MyClickHandler(ByVal sender As Object, ByVal e As EventArgs)
            MessageBox.Show("My Menu Item Clicked!")
        End Sub