ModifyMenu function

Changes an existing menu item. This function is used to specify the content, appearance, and behavior of the menu item.

Syntax

BOOL WINAPI ModifyMenu(
  _In_     HMENU    hMnu,
  _In_     UINT     uPosition,
  _In_     UINT     uFlags,
  _In_     UINT_PTR uIDNewItem,
  _In_opt_ LPCTSTR  lpNewItem
);

Parameters

hMnu [in]

Type: HMENU

A handle to the menu to be changed.

uPosition [in]

Type: UINT

The menu item to be changed, as determined by the uFlags parameter.

uFlags [in]

Type: UINT

Controls the interpretation of the uPosition parameter and the content, appearance, and behavior of the menu item. This parameter must include one of the following required values.

Value	Meaning
MF_BYCOMMAND 0x00000000L	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 0x00000400L	Indicates that the uPosition parameter gives the zero-based relative position of the menu item.

 

The parameter must also include at least one of the following values.

Value	Meaning
MF_BITMAP 0x00000004L	Uses a bitmap as the menu item. The lpNewItem parameter contains a handle to the bitmap.
MF_CHECKED 0x00000008L	Places a check mark next to the item. If your application provides check-mark bitmaps (see the SetMenuItemBitmaps function), this flag displays a selected bitmap next to the menu item.
MF_DISABLED 0x00000002L	Disables the menu item so that it cannot be selected, but this flag does not gray it.
MF_ENABLED 0x00000000L	Enables the menu item so that it can be selected and restores it from its grayed state.
MF_GRAYED 0x00000001L	Disables the menu item and grays it so that it cannot be selected.
MF_MENUBARBREAK 0x00000020L	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 0x00000040L	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 0x00000100L	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 0x00000010L	Specifies that the menu item opens a drop-down menu or submenu. The uIDNewItem parameter specifies a handle to 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 0x00000800L	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 0x00000000L	Specifies that the menu item is a text string; the lpNewItem parameter is a pointer to the string.
MF_UNCHECKED 0x00000000L	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 a clear bitmap next to the menu item.

 

uIDNewItem [in]

Type: UINT_PTR

The identifier of the modified menu item or, if the uFlags parameter has the MF_POPUP flag set, a handle to the drop-down menu or submenu.

lpNewItem [in, optional]

Type: LPCTSTR

The contents 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 0x00000004L	A bitmap handle.
MF_OWNERDRAW 0x00000100L	A 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 0x00000000L	A pointer to a null-terminated string (the default).

 

Return value

Type: BOOL

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.

In order for keyboard accelerators to work with bitmap or owner-drawn menu items, the owner of the menu must process the WM_MENUCHAR message. See Owner-Drawn Menus and the WM_MENUCHAR Message for more information.

The application must call the DrawMenuBar function whenever a menu changes, whether 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 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

Examples

For an example, see Setting Fonts for Menu-Item Text Strings.

Requirements

See also

Reference

AppendMenu

CheckMenuItem

DrawMenuBar

EnableMenuItem

SetMenuItemBitmaps

SetMenuItemInfo

Conceptual

Menus