WM_INITMENUPOPUP

The WM_INITMENUPOPUP message is sent when a drop-down menu or submenu is about to become active. This allows an application to modify the menu before it is displayed, without changing the entire menu.

WM_INITMENUPOPUP 
hmenuPopup = (HMENU) wParam;         // handle to submenu
uPos = (UINT) LOWORD(lParam);        // submenu item position 
fSystemMenu = (BOOL) HIWORD(lParam); // window menu flag 
 

Parameters

hmenuPopup

Value of wParam. Handle to the drop-down menu or submenu.

uPos

Value of the low-order word of lParam. Specifies the zero-based relative position of the menu item that opens the drop-down menu or submenu.

fSystemMenu

Value of the high-order word of lParam. Specifies whether the drop-down menu is the window menu (also known as the System menu or the Control menu). If the menu is the window menu, this parameter is TRUE; otherwise, it is FALSE.

Return Values

If an application processes this message, it should return zero.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Requires version 1.0 or later.
  Header: Declared in winuser.h.

See Also

Keyboard Accelerators Overview, Keyboard Accelerator Messages, WM_INITMENU