I have an C++ MFC CMenu based context menu object that has several menu items and one menu item is a popup menu (ie has a sub menu). Populating the sub menu is a time intensive process so I don't want to actually populate it until the user clicks on it.
How do I detect the display of the sub menu so I can only populate it when the user clicks on it?
I'm using TrackPopupMenu to display the menu to the user.
You want WM_INITMENUPOPUP.