DisableItem
DisableItem Dim a menu or a menu item; make non-selec table short whichItem ; item ID of item to disable; 0=entire menu
DisableItem dims a menu title or an individual item in a menu. When disabled, the item (or menu) is not highlighted when the cursor moves over it
and cannot be selected.
theMenu is a handle leading to a variable-length MenuInfo structure. It is a containing the item to disable, or if whichItem = 0, the menu to
disable.
whichItem identifies which item to disable or specifies your intention to
disable an entire menu. When whichItem=0, the menu title is
dimmed and all items in that menu are disabled. If it is a valid item
ID, it specifies an item in theMenu. Items are numbered sequentially
with the topmost item having an ID of 1; the last item ID can be
Notes: Use DisableItem on all menu items that are not valid in the current context; e.g., disable "Paste" when there is nothing in the paste buffer.
Disabling an item also excludes it from the search performed by
When you disable or re-enable an entire menu ( whichItem =0), you
should call DrawMenuBar to display the changed menu title. This works by clearing bit number whichItem in the enableFlags field of
the relevant MenuInfo structure. For instance, the following calls are functionally equivalent:
(*myMenu)-> enableFlags &= ~4; /* clear bit 2 */
All menus and items are implicitly enabled when inserted into the menu
unless explicitly disabled by including the (" metacharacter in the item
text. Items with IDs higher than 31 are always enabled, since there is no
"enable flag" to control them.