ModifyMenu
The ModifyMenu
function changes an existing menu item. This function is used to specify the
content, appearance, and behavior of the menu item.
The ModifyMenu
function has been superseded by the SetMenuItemInfo function. You can still use
ModifyMenu, however, if you do not need any of the extended features of SetMenuItemInfo.
BOOL ModifyMenu(
|
HMENU hMnu, |
// handle of menu |
|
UINT uPosition, |
// menu item to
modify |
|
UINT uFlags, |
// menu item flags |
|
UINT uIDNewItem, |
// menu item
identifier or handle of drop-down menu or submenu |
|
LPCTSTR lpNewItem |
// menu item
content |
|
); |
|
Parameters
hMnu
Identifies
the menu to be changed.
uPosition
Specifies the
menu item to be changed, as determined by the uFlags parameter.
uFlags
Specifies
flags that control the interpretation of the uPosition parameter and the
content, appearance, and behavior of the menu item. This parameter must be a
combination of one of the following required values and at least one of the
values listed in the following Remarks section.
|
Value |
Meaning |
|
MF_BYCOMMAND |
Indicates
that the uPosition parameter gives the identifier of the menu item.
The MF_BYCOMMAND flag is the default if neither the MF_BYCOMMAND nor
MF_BYPOSITION flag is specified. |
|
MF_BYPOSITION |
Indicates
that the uPosition parameter gives the zero-based relative position of
the menu item. |
uIDNewItem
Specifies
either the identifier of the modified menu item or, if the uFlags
parameter has the MF_POPUP flag set, the handle of the drop-down menu or
submenu.
lpNewItem
Points to the
content of the changed menu item. The interpretation of this parameter depends
on whether the uFlags parameter includes the MF_BITMAP, MF_OWNERDRAW, or
MF_STRING flag.
|
Value |
Meaning |
|
MF_BITMAP |
Contains a
bitmap handle. |
|
MF_OWNERDRAW |
Contains a
32-bit value supplied by an application that is used to maintain additional
data related to the menu item. The value is in the itemData member of
the structure pointed to by the lparam parameter of the WM_MEASUREITEM or WM_DRAWITEM messages sent when the menu
item is created or its appearance is updated. |
|
MF_STRING |
Contains a
pointer to a null-terminated string (the default). |
Return Values
If the
function succeeds, the return value is nonzero.
If the function
fails, the return value is zero. To get extended error information, call GetLastError.
Remarks
If ModifyMenu
replaces a menu item that opens a drop-down menu or submenu, the function
destroys the old drop-down menu or submenu and frees the memory used by it.
The
application must call the DrawMenuBar function whenever a menu changes, whether or
not the menu is in a displayed window. To change the attributes of existing
menu items, it is much faster to use the CheckMenuItem and EnableMenuItem functions.
The following
list describes the flags that may be set in the uFlags parameter:
|
Value |
Meaning |
|
MF_BITMAP |
Uses a
bitmap as the menu item. The lpNewItem parameter contains the handle
of the bitmap. |
|
MF_BYCOMMAND |
Indicates
that the uPosition parameter specifies the identifier of the menu item
(the default). |
|
MF_BYPOSITION |
Indicates
that the uPosition parameter specifies the zero-based relative
position of the new menu item. |
|
MF_CHECKED |
Places a
check mark next to the item. If your application provides check mark bitmaps
(see the SetMenuItemBitmaps function), this flag displays a checked
bitmap next to the menu item. |
|
MF_DISABLED |
Disables
the menu item so that it cannot be selected, but this flag does not gray it. |
|
MF_ENABLED |
Enables the
menu item so that it can be selected and restores it from its grayed state. |
|
MF_GRAYED |
Disables
the menu item and grays it so that it cannot be selected. |
|
MF_MENUBARBREAK |
Functions
the same as the MF_MENUBREAK flag for a menu bar. For a drop-down menu,
submenu, or shortcut menu, the new column is separated from the old column by
a vertical line. |
|
MF_MENUBREAK |
Places the
item on a new line (for menu bars) or in a new column (for a drop-down menu,
submenu, or shortcut menu) without separating columns. |
|
MF_OWNERDRAW |
Specifies
that the item is an owner-drawn item. Before the menu is displayed for the
first time, the window that owns the menu receives a WM_MEASUREITEM message to retrieve the width
and height of the menu item. The WM_DRAWITEM message is then sent to the window procedure of
the owner window whenever the appearance of the menu item must be updated. |
|
MF_POPUP |
Specifies
that the menu item opens a drop-down menu or submenu. The uIDNewItem
parameter specifies the handle of the drop-down menu or submenu. This flag is
used to add a menu name to a menu bar or a menu item that opens a submenu to
a drop-down menu, submenu, or shortcut menu. |
|
MF_SEPARATOR |
Draws a
horizontal dividing line. This flag is used only in a drop-down menu, submenu,
or shortcut menu. The line cannot be grayed, disabled, or highlighted. The lpNewItem
and uIDNewItem parameters are ignored. |
|
MF_STRING |
Specifies
that the menu item is a text string; the lpNewItem parameter points to
the string. |
|
MF_UNCHECKED |
Does not
place a check mark next to the item (the default). If your application
supplies check mark bitmaps (see the SetMenuItemBitmaps function), this
flag displays an unchecked bitmap next to the menu item. |
The following
groups of flags cannot be used together:
MF_BYCOMMAND and MF_BYPOSITION
MF_DISABLED, MF_ENABLED, and
MF_GRAYED
MF_BITMAP, MF_STRING,
MF_OWNERDRAW, and MF_SEPARATOR
MF_MENUBARBREAK and
MF_MENUBREAK
MF_CHECKED and MF_UNCHECKED
See Also