Q129224: HOWTO: Remove the System Menu from an Iconized Application
Article: Q129224
Product(s): Microsoft C Compiler
Version(s): 1.0,1.5,1.51,1.52,2.0,2.1,4.0,5.0,6.0
Operating System(s):
Keyword(s): kbcode kbMenu kbMFC KbUIDesign kbVC100 kbVC150 kbVC200 kbVC400 kbVC500 kbVC600 kbGrpDSM
Last Modified: 26-MAR-2002
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The information in this article applies to:
- The Microsoft Foundation Classes (MFC), used with:
- Microsoft Visual C++ for Windows, 16-bit edition, versions 1.0, 1.5, 1.51, 1.52
- Microsoft Visual C++, 32-bit Editions, versions 2.0, 2.1, 4.0
- Microsoft Visual C++, 32-bit Enterprise Edition, versions 5.0, 6.0
- Microsoft Visual C++, 32-bit Professional Edition, versions 5.0, 6.0
- Microsoft Visual C++, 32-bit Learning Edition, version 6.0
- Microsoft Visual C++.NET (2002)
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SUMMARY
=======
There are two ways to remove the system menu of an application when a user
clicks an iconized application:
1. Override the main frame window's PreCreateWindow function to remove the
WS_SYSMENU from the window's style field. However, this method removes the
system menu altogether from the application.
2. Override the main frame window's OnSize method, and change the window style
of the mainframe to either include or exclude the WS_SYSMENU style bit
depending on user action. Use this technique if the user wants to remove the
system menu when the application is iconized and add the system menu back to
the application when the application is restored.
MORE INFORMATION
================
Method One
----------
To remove the system menu completely from the application, override the main
frame window's PreCreateWindow method as follows:
BOOL CMainFrame::PreCreateWindow(CREATESTRUCT & cs)
{
// Call the base class version of PreCreateWindow, replace
// CMDIFrameWnd with CFrameWnd in the following line
// for an SDI application
if (!CMDIFrameWnd::PreCreateWindow(cs))
return FALSE;
// Remove the system menu style bit from the window
cs.style &= ~WS_SYSMENU;
return TRUE;
}
Method Two
----------
The following steps and code fragments show how to remove the system menu when a
user clicks an iconized application. The system menu is restored when the
application is not iconized.
1. Declare a BOOLEAN public data member in the class declaration of CMainFrame.
This data member determines if the system menu is enabled or not:
// In an SDI application CMainFrame will be derived from CFrameWnd
class CMainFrame : public CMDIFrameWnd
{
public:
BOOL sys_menu_enabled;
.
. // Existing class declarations
.
}
2. Modify the CMainFrame constructor to initialize the sys_menu_enabled data
member function to TRUE:
CMainFrame::CMainFrame()
{
//default the system menu to be enabled
sys_menu_enabled = TRUE;
.
. // Continue with normal constructor code, if any
.
}
3. Create a message handler for the WM_SIZE message for the CMainFrame class,
and add the following code to the CMainFrame::OnSize message handler:
void CMainFrame::OnSize(UINT nType, int cx, int cy)
{
// declare a local variable to hold the window style
long window_style;
//call base class's OnSize function,
//If SDI application call CFrameWnd::OnSize()
CMDIFrameWnd::OnSize(nType, cx, cy);
//if user is minimizing or iconizing the application
if (nType == SIZE_MINIMIZED)
{
// Get the main frame window's style
window_style = GetWindowLong(m_hWnd, GWL_STYLE);
//Remove the system menu from the window's style
window_style &= ~WS_SYSMENU;
//toggle the boolean data member to show sys menu disabled
sys_menu_enabled = FALSE;
//set the style attribute of the main frame window
SetWindowLong(m_hWnd, GWL_STYLE, window_style);
}
else
{
//if user is restoring the application and his system menu
//is disabled,
if ((nType == SIZE_RESTORED) || nType == SIZE_MAXIMIZED) &&
(!sys_menu_enabled))
{
window_style = GetWindowLong(m_hWnd, GWL_STYLE);
//Add the system menu to the window's style
window_style |= WS_SYSMENU;
//toggle the boolean data member to show sys menu enabled
sys_menu_enabled = TRUE;
SetWindowLong(m_hWnd, GWL_STYLE, window_style);
SendMessage(WM_NCACTIVATE,TRUE);
}
}
}
Additional query words:
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Keywords : kbcode kbMenu kbMFC KbUIDesign kbVC100 kbVC150 kbVC200 kbVC400 kbVC500 kbVC600 kbGrpDSMFCATL
Technology : kbAudDeveloper kbMFC
Version : :1.0,1.5,1.51,1.52,2.0,2.1,4.0,5.0,6.0
Issue type : kbhowto
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