mfc中窗体右键菜单项灰化问题？

mfc中窗体右键菜单项灰化问题？

CPoint MousePos;        GetCursorPos(&MousePos);        CMenu menu;        menu.LoadMenuW(IDR_MENU1);        SetForegroundWindow();        CMenu* pMenu=menu.GetSubMenu(0);        CMenu* ppMenu=pMenu->GetSubMenu(0);        TStreamStatus status1;        player->GetStatus(&status1);        if(!m_IsPlay)        {           // MF_GRAYED 灰化            ppMenu->ModifyMenuW(0,MF_BYPOSITION|MF_GRAYED,ID_32785,_T("播放"));            ppMenu->ModifyMenuW(1,MF_BYPOSITION|MF_GRAYED,ID_32783,_T("上一曲(&S)"));            ppMenu->ModifyMenuW(2,MF_BYPOSITION|MF_GRAYED,ID_32784,_T("下一曲(&N)"));        }