WebControl.PresentContextualMenu
From Xojo Documentation
Method
PresentContextualMenu displays the contextual menu assigned to the WebControl.
Notes
By using this method, the user does not need to right+click to trigger the contextual menu. For example, if PresentContextualMenu is called in the MouseEnter event, the contextual menu will display whenever the mouse enters the control.
To use a menu as a contextualmenu, use the ContextualMenu property. The menu will be shown as a contextual menu when the user right-clicks on the WebControl.
Regardless of whether the menu is displayed by right-clicking or by calling PresentContextualMenu, the ContextualMenuAction event handler is called when a menu is selected.
Example
Display the contextual menu attached to a Button:
Button1.PresentContextualMenu