求助，关于多文档的全屏问题

我的代码在单文档界面比较好用，但是在多文档的情况下，全屏不彻底，下面有一个窄条没有添满。我看到有人回答过这个问题，说和WS_POPUPWINDOW有关，但是我打不开那个网页，只好来这里问高手了。我的代码如下：
首先在MainFrm.h中
BOOL             m_FullScreen;
WINDOWPLACEMENT  m_WPPrev;
         CRect         m_FullScreenWindowRect;
CToolBar         *m_pWndFullScreenBar;
然后
void CMainFrame::OnFullScreen()
{
RECT DesktopRect;
    WINDOWPLACEMENT WPNew;

m_FullScreen = m_FullScreen ? TRUE : FALSE;

    if(!m_FullScreen)
{
        // need to hide all status bars
        m_wndStatusBar.ShowWindow(SW_HIDE);
       //隐藏工具条
m_wndToolBar.ShowWindow(SW_HIDE);
m_Layout.ShowWindow(SW_HIDE);
m_LayoutGL.ShowWindow(SW_HIDE);

// We'll need these to restore the original state.
GetWindowPlacement (&m_WPPrev);

m_WPPrev.length = sizeof m_WPPrev;

        //Adjust RECT to new size of window
::GetWindowRect(::GetDesktopWindow(), &DesktopRect);

DesktopRect.left -= 1;
DesktopRect.top -= 1;
DesktopRect.bottom += 2;
DesktopRect.right += 2;

      ::AdjustWindowRectEx(&DesktopRect, GetStyle(), TRUE, GetExStyle());

// Remember this for OnGetMinMaxInfo()
m_FullScreenWindowRect = DesktopRect;
        
        WPNew = m_WPPrev;
        WPNew.showCmd =  SW_SHOWNORMAL;
WPNew.rcNormalPosition = DesktopRect;

        m_pWndFullScreenBar=new CToolBar;

        
        if(!m_pWndFullScreenBar->Create(this,CBRS_SIZE_DYNAMIC|CBRS_FLOATING) ||
         !m_pWndFullScreenBar->LoadToolBar(IDR_FULLSCREEN_GLTOOL))
         {
         TRACE0("Failed to create toolbar\n");
         return; // fail to create
         }
        
        
        //don't allow the toolbar to dock
        m_pWndFullScreenBar->EnableDocking(0);
m_pWndFullScreenBar->SetWindowPos(0, 0,0, 0,0,SWP_NOSIZE|SWP_NOZORDER|SWP_NOACTIVATE|SWP_SHOWWINDOW);
m_pWndFullScreenBar->SetWindowText(_T("Hold Ctrl+F to switch between normal and a full screen"));
FloatControlBar(m_pWndFullScreenBar, CPoint(0,0));
m_pWndFullScreenBar->EnableToolTips(TRUE);
m_FullScreen=TRUE;
m_Workshop.ShowWindow(SW_HIDE);
}
    else
{
        m_pWndFullScreenBar->DestroyWindow();
delete m_pWndFullScreenBar;

        m_FullScreen=FALSE;

        m_wndStatusBar.ShowWindow(SW_SHOWNORMAL);
m_wndToolBar.ShowWindow(SW_SHOWNORMAL);
m_Layout.ShowWindow(SW_SHOWNORMAL);
m_LayoutGL.ShowWindow(SW_SHOWNORMAL);
m_Workshop.ShowWindow(SW_SHOWNORMAL);
        WPNew = m_WPPrev;
}
    
    SetWindowPlacement(&WPNew);
}void CMainFrame::OnGetMinMaxInfo(MINMAXINFO FAR* lpMMI) 
{
if(m_FullScreen)
{
lpMMI->ptMaxSize.y = m_FullScreenWindowRect.Height();
lpMMI->ptMaxTrackSize.y = lpMMI->ptMaxSize.y;
lpMMI->ptMaxSize.x = m_FullScreenWindowRect.Width();
lpMMI->ptMaxTrackSize.x = lpMMI->ptMaxSize.x;
}
// CCJFrameWnd::OnGetMinMaxInfo(lpMMI);//必须注销，否则不能编译通过
}