The GetSystemMenu function allows the application to access the window menu (also known as the system menu or the control menu) for copying and modifying.
HMENU GetSystemMenu(
HWND hWnd, // handle to window to own window menu
BOOL bRevert // reset flag
);
If this parameter is TRUE, GetSystemMenu resets the window menu back to the default state. The previous window menu, if any, is destroyed.
If the bRevert parameter is FALSE, the return value is the handle to a copy of the window menu. If the bRevert parameter is TRUE, the return value is NULL.
Any window that does not use the GetSystemMenu function to make its own copy of the window menu receives the standard window menu.
The window menu initially contains items with various identifier values, such as SC_CLOSE, SC_MOVE, and SC_SIZE.
Menu items on the window menu send WM_SYSCOMMAND messages.
All predefined window menu items have identifier numbers greater than 0xF000. If an application adds commands to the window menu, it should use identifier numbers less than 0xF000.
The system automatically grays items on the standard window menu, depending on the situation. The application can perform its own checking or graying by responding to the WM_INITMENU message that is sent before any menu is displayed.
Windows CE: Windows CE does not support a system menu, but GetSystemMenu is implemented as a macro to maintain compatibility with existing code. You can use the menu handle returned by this macro to disable the close box the same way you would in a Windows desktop platform. There is no other use for the return value in Windows CE. The brevert parameter is ignored. Use the following code to disable the Close button:
EnableMenuItem (GetSystemMenu(hwnd, FALSE), SC_CLOSE,MF_BYCOMMAND | MF_GRAYED);
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.
Import Library: Use user32.lib.
Menus Overview, Menu Functions, GetMenu, WM_INITMENU, WM_SYSCOMMAND