ID Number: Q71669
3.00
MS-DOS
Summary:
In an application using the Windows version 3.00 multiple document
interface (MDI), MDI child windows are always created with a maximize
button, a minimize button, and a thick "sizing" border. Currently, it
is not possible to modify this default behavior.
However, it is possible to prevent an MDI child from being maximized,
minimized, or sized. This can be done by performing two steps:
1. Disable the Maximize, Minimize, and Size options on the child
window's system menu.
2. Trap the appropriate WM_SYSCOMMAND messages in the MDI child
window's window procedure.
This article contains a sample MDI child window procedure that
illustrates this technique.
More Information:
The following sample MDI child window procedure can be used to
implement an MDI child that can not be maximized, minimized or sized:
LONG FAR PASCAL SampleMDIChildWndProc(hWnd, msg, wParam, lParam)
HWND hWnd;
WORD msg;
WORD wParam;
LONG lParam;
// This sample MDI child window procedure can be used to prevent the
// MDI child from being maximized, minimized, or sized.
//
// Note that the child will still have a maximize button, a minimize
// button, and a thick "sizing" border. Currently, there is no way to
// prevent Windows from creating MDI children with these default
// styles.
//
// We can, however, disable the maximizing, minimizing, and sizing
// functionality by:
//
// 1. Disabling system menu options
// 2. Trapping WM_SYSCOMMAND messages
{
HMENU hSystemMenu; // the MDI child's system menu
switch (msg)
{
case WM_INITMENU:
// Disable and gray the Maximize, Minimize, and Size items
// on the MDI child's system menu
hSystemMenu = GetSystemMenu(hWnd, FALSE);
EnableMenuItem(hSystemMenu, SC_MAXIMIZE, MF_GRAYED |
MF_BYCOMMAND);
EnableMenuItem(hSystemMenu, SC_MINIMIZE, MF_GRAYED |
MF_BYCOMMAND);
EnableMenuItem(hSystemMenu, SC_SIZE, MF_GRAYED |
MF_BYCOMMAND);
break;
case WM_SYSCOMMAND:
// "Eat" these system commands to disable maximizing,
// minimizing, and sizing functionality.
// Note that wParam must be combined with 0xFFF0, using
// the C bitwise AND (&) operator, when processing
// the WM_SYSCOMMAND message.
switch (wParam & 0xFFF0)
{
case SC_MAXIMIZE:
case SC_MINIMIZE:
case SC_SIZE:
return 1L;
default:
break;
}
break;
default:
break;
}
return DefMDIChildProc(hWnd, msg, wParam, lParam);
}
For more information on Windows MDI, query on the following words:
prod(winsdk) and MDI