RibbonButton.Menu

Property (As MenuItem)

aRibbonButton.Menu = newValue
or
MenuItemValue = aRibbonButton.Menu

The Menu to display if HasMenu is True.

Menu is an instance of MenuItem.

The following code will add a Menu to a button

 Dim bt As RibbonButton
 bt = Ribbon.GetButton("Save")
 bt.HasMenu = True
 
 Dim base As New MenuItem
 base.Append New MenuItem("First action")
 base.Append New MenuItem("Second action")
 base.Append New MenuItem(MenuItem.TextSeparator)
 base.Append New MenuItem("Third action")
 
 bt.Menu = base

The clicked item from the menu is handled in the RibbonCanvas.MenuAction event