CToolTipCtrl m_pToolTipCtrl不能在OnCreate()里?//内存异常

lass CMainFrame : public CFrameWnd
类的声明一个  CToolTipCtrl m_pToolTipCtrl成员;

 int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
    if (CFrameWnd::OnCreate(lpCreateStruct) == -1)
        return -1;

    if (!m_wndToolBar.CreateEx(this, TBSTYLE_FLAT, WS_CHILD | WS_VISIBLE | CBRS_TOP
        | CBRS_GRIPPER | CBRS_TOOLTIPS | CBRS_FLYBY | CBRS_SIZE_DYNAMIC) ||
        !m_wndToolBar.LoadToolBar(IDR_MAINFRAME))
    {
        TRACE0("未能创建工具栏\n");
        return -1;      // 未能创建
    }

    //////////////////////////////////////////////////////////////////////
    m_Imagelist.Create(32,32,ILC_COLOR32 | ILC_MASK,0,0);  //创建图像列表

    m_Imagelist.Add(AfxGetApp()->LoadIcon(IDI_ICON_SET));
    m_Imagelist.Add(AfxGetApp()->LoadIcon(IDI_ICON_TIMER));
    m_Imagelist.Add(AfxGetApp()->LoadIcon(IDI_ICON_PAN));
    m_Imagelist.Add(AfxGetApp()->LoadIcon(IDI_ZOOM_IN)); 
    m_Imagelist.Add(AfxGetApp()->LoadIcon(IDI_ZOOM_OUT)); 
    //CListCtrl m_listCtrl;
    //m_listCtrl.SetImageList(&m_Imagelist,LVSIL_NORMAL);
    UINT nArray[5] = { ID_MENU_AUTOTEST, ID_MENU_PERIOD_CHECK, ID_TOOL_PAN,ID_TOOL_ZOOMIN,ID_TOOL_ZOOMOUT};  
    m_wndToolBar.SetButtons(nArray, 5);

    m_wndToolBar.GetToolBarCtrl().SetButtonSize(CSize(41,41));
    m_wndToolBar.GetToolBarCtrl().SetBitmapSize(CSize(36,36));

    

    m_wndToolBar.GetToolBarCtrl().SetImageList(&m_Imagelist);

    if (!m_wndStatusBar.Create(this) ||
        !m_wndStatusBar.SetIndicators(indicators,
          sizeof(indicators)/sizeof(UINT)))
    {
        TRACE0("未能创建状态栏\n");
        return -1;      // 未能创建
    }

    // TODO: 如果不需要工具栏可停靠，则删除这三行
    m_wndToolBar.EnableDocking(CBRS_ALIGN_ANY);
    EnableDocking(CBRS_ALIGN_ANY);
    DockControlBar(&m_wndToolBar);

    CPAIBaseDialog::AddWndIdToMap(m_iWndID,this);
    StartHeartbeat();
    if (g_shUserType != 1)
    {
        
        HICON hIcon=AfxGetApp()->LoadIcon(IDI_ICON6);
        m_Imagelist.Replace(0,hIcon);
        hIcon = AfxGetApp()->LoadIcon(IDI_ICON7);
        m_Imagelist.Replace(1,hIcon);
        SignIcon=0;
    }
    m_pToolTipCtrl.Create(this);
    m_pToolTipCtrl.AddTool(GetDlgItem(IDI_ICON6),"123");//这行代码编译过，运行内存错误!
    return 0;
}