Dynamic menu using mfc

I would like to add a menu item to my main menu and then populate it with items at run time. How would I do this? And besides adding items how would I have a message map entry 开发者_运维百科for them since I do not know the id?

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You can create a CMenu object dynamically like this:

CMenu *menu = new CMenu;
menu->CreatePopupMenu();
// Add items to the menu
menu->AppendMenu(MF_STRING, menuItemID, "Text");
...

Then add this sub-menu to your main menu:

wnd->GetMenu()->AppendMenu(MF_POPUP, (UINT_PTR)menu->m_hMenu, "Menu Name");

As for the message map, assuming all your menu item IDs are within a certain range, you can use ON_COMMAND_RANGE to map the entire range to a single function. This function will receive the ID as a parameter, and within the function, you can perform different operations based on the ID.

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define the menu's using #define

#define ID_SHOW   2002
#define ID_HIDE   2004

//create a menu object for main menu
CMenu *menu    = new CMenu();
menu->CreateMenu();

//another menu object for submenu
CMenu *subMenu = new CMenu();
subMenu->CreatePopupMenu();
subMenu->AppendMenu(MF_STRING, ID_HIDE, _T("four"));
subMenu->AppendMenu(MF_STRING, ID_SHOW, _T("three"));
//append submenu to menu
menu->AppendMenu(MF_POPUP|MF_STRING, (UINT)subMenu->m_hMenu,  _T("Advanced") );
SetMenu(menu);

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  CMenu menuPopup;
  menuPopup.LoadMenu(IDR_CNTXT_PLAN);
subMenu.CreatePopupMenu();
 subMenu.AppendMenu(MF_STRING, MENU1,"Menu1");
subMenu.AppendMenu(MF_STRING, MENU2,"Menu2");
CMenu* pMenu = menuPopup.GetSubMenu(0);
  pMenu->InsertMenu(0,MF_BYPOSITION|MF_POPUP,(UINT)subMenu.m_hMenu,"Layers");
  menuPopup.GetSubMenu(0)->InsertMenu(1,MF_BYPOSITION|MF_SEPARATOR,0,"");
menuPopup.GetSubMenu(0)->TrackPopupMenu(TPM_LEFTALIGN, point.x, point.y, this);

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Following example if you wish to dynamically add menu item & also attach data to that menu item.

    struct MyStruct
    {
        int abc;
    };
    CMenu MyMenu;
    MyMenu.CreatePopupMenu();

    CMenu MyMainMenu;
    VERIFY(MyMainMenu.LoadMenu(IDR_MAIN_MENU_ID));
    MyMainMenu.InsertMenu(0, MF_POPUP, (UINT_PTR)MyMenu.m_hMenu, _T("Main Menu"));

    const int iMenuAdds = 5;
    for (int i = 0; i < iMenuAdds; ++i)
    {
        MyStruct myStruct;
        myStruct.abc = i+10001;

        CString MenuDesc;
        MenuDesc.Format(_T("MenuNo: %d"), i);
        MENUITEMINFO tmpItem;
        tmpItem.fMask = MIIM_STRING | MIIM_ID | MIIM_DATA;
        tmpItem.fType = MFT_STRING;
        tmpItem.fState = MFS_ENABLED;
        tmpItem.wID = i + 101; //See note 1. below.
        tmpItem.dwItemData = (ULONG_PTR)&myStruct; //data set.
        tmpItem.dwTypeData = MenuDesc.GetBuffer(); //string description
        tmpItem.cch = MenuDesc.GetLength();
        tmpItem.cbSize = sizeof(tmpItem);
        MyMenu.InsertMenuItem(i, (LPMENUITEMINFO)& tmpItem, FALSE);
    }

To retrieve menu item & associated data:

CMenu* pPopup = &MyMenu; //or CMenu* pPopup = MyMainMenu.GetSubMenu(0); depending on parent.
ULONG_PTR lRetVal = pPopup->TrackPopupMenu(TPM_LEFTALIGN | TPM_RIGHTBUTTON | TPM_RETURNCMD, point.x, point.y, this, NULL);
//^^lRetVal should return same value as tmpItem.wID above.

MENUITEMINFO tmpItem;
tmpItem.cbSize = sizeof(MENUITEMINFO);
tmpItem.fMask = MIIM_STRING | MIIM_ID | MIIM_DATA;
tmpItem.fType = MFT_STRING;
TCHAR dwTypeData[256];
tmpItem.dwTypeData = dwTypeData;
tmpItem.cch = 256;
pPopup->GetMenuItemInfo(lRetVal, &tmpItem, FALSE);
MyStruct *myStruct = (MyStruct*)tmpItem.dwItemData; //and now we have our data.

1. Used as your #define & can be used for ON_COMMAND_RANGE(idFirst, idLast, Function), so would still need to have some sort of defined range if you were planning on using ON_COMMAND_RANGE. Alternatively: use command range for dynamic menu or create your own within the data set. Also need to make sure any ranges used do not conflict with any already #defined menu items on the same or parent menu.

Added above as I found this thread from googling due to an issue & I was already using the accepted answers method for adding menu items.