using DevExpress.Utils.Menu;
using DevExpress.XtraScheduler;
using DevExpress.XtraScheduler.Services;
using DevExpress.XtraScheduler.Commands;
// ...
void schedulerControl1_PopupMenuShowing(object sender, PopupMenuShowingEventArgs e) {
    if (e.MenuType == DevExpress.XtraScheduler.Views.SchedulerMenuType.DefaultMenu) {
        // Hide the "Change View To" menu item
        SchedulerPopupMenu itemChangeViewTo = e.Menu.GetPopupMenuById(SchedulerMenuItemId.SwitchViewMenu);
        itemChangeViewTo.Visible = false;

        // Remove unnecessary items
        e.Menu.RemoveMenuItem(SchedulerMenuItemId.NewAllDayEvent);

        // Disable the "New Recurring Appointment" menu item
        e.Menu.DisableMenuItem(SchedulerMenuItemId.NewRecurringAppointment);

        // Rename the "New Appointment" menu item
        SchedulerMenuItem item = e.Menu.GetMenuItemById(SchedulerMenuItemId.NewAppointment);
        if (item != null) {
            item.Caption = "&New Meeting";
            item.ImageOptions.SvgImage = DevExpress.Utils.Svg.SvgImage.FromFile("NewItem.svg");
        }

        // Display a new menu item for a SchedulerCommand
        ISchedulerCommandFactoryService service = schedulerControl1.GetService<ISchedulerCommandFactoryService>();
        SchedulerCommand cmd = service.CreateCommand(SchedulerCommandId.SwitchToGroupByResource);
        SchedulerMenuItemCommandWinAdapter menuItemCommandAdapter =
            new SchedulerMenuItemCommandWinAdapter(cmd);
        DXMenuItem menuItem = (DXMenuItem)menuItemCommandAdapter.CreateMenuItem(DXMenuItemPriority.Normal);
        menuItem.BeginGroup = true;
        e.Menu.Items.Add(menuItem);

        // Display a new menu item and handle its Click event
        e.Menu.Items.Add(new SchedulerMenuItem("Click me!", MyClickHandler));
    }
}

public void MyClickHandler(object sender, EventArgs e) {
    MessageBox.Show("My menu item was clicked!");
}

Imports DevExpress.Utils.Menu
Imports DevExpress.XtraScheduler
Imports DevExpress.XtraScheduler.Services
Imports DevExpress.XtraScheduler.Commands
' ...
Private Sub schedulerControl1_PopupMenuShowing(ByVal sender As Object, ByVal e As PopupMenuShowingEventArgs) Handles schedulerControl1.PopupMenuShowing
    If e.MenuType = DevExpress.XtraScheduler.Views.SchedulerMenuType.DefaultMenu Then
        Dim itemChangeViewTo As SchedulerPopupMenu = e.Menu.GetPopupMenuById(SchedulerMenuItemId.SwitchViewMenu)
        itemChangeViewTo.Visible = False

        e.Menu.RemoveMenuItem(SchedulerMenuItemId.NewAllDayEvent)
        e.Menu.DisableMenuItem(SchedulerMenuItemId.NewRecurringAppointment)

        Dim item As SchedulerMenuItem = e.Menu.GetMenuItemById(SchedulerMenuItemId.NewAppointment)
                If item IsNot Nothing Then
                    item.Caption = "&New Meeting"
                    item.ImageOptions.SvgImage = DevExpress.Utils.Svg.SvgImage.FromFile("NewItem.svg")
                End If

        Dim service As ISchedulerCommandFactoryService = schedulerControl1.GetService(Of ISchedulerCommandFactoryService)()
        Dim cmd As SchedulerCommand = service.CreateCommand(SchedulerCommandId.SwitchToGroupByResource)
        Dim menuItemCommandAdapter As New SchedulerMenuItemCommandWinAdapter(cmd)
        Dim menuItem As DXMenuItem = CType(menuItemCommandAdapter.CreateMenuItem(DXMenuItemPriority.Normal), DXMenuItem)
        menuItem.BeginGroup = True
        e.Menu.Items.Add(menuItem)

        e.Menu.Items.Add(New SchedulerMenuItem("Click me!", AddressOf MyClickHandler))
    End If
End Sub

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