为什么我在任务栏里图标没有显示

int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
if (CMDIFrameWnd::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("Failed to create toolbar\n");
return -1; // fail to create
}

if (!m_wndStatusBar.Create(this) ||
!m_wndStatusBar.SetIndicators(indicators,
sizeof(indicators)/sizeof(UINT)))
{
TRACE0("Failed to create status bar\n");
return -1; // fail to create
}

// TODO: Delete these three lines if you don't want the toolbar to
// be dockable
m_wndToolBar.EnableDocking(CBRS_ALIGN_ANY);
EnableDocking(CBRS_ALIGN_ANY);
DockControlBar(&m_wndToolBar);

NOTIFYICONDATA tnd;
tnd.cbSize=sizeof(NOTIFYICONDATA);
tnd.hWnd=this->m_hWnd;
tnd.uID=IDR_ONLINE; //我画的图标
tnd.uFlags=NIF_MESSAGE|NIF_ICON|NIF_TIP;
tnd.uCallbackMessage=WM_MOUSEDOWN;
tnd.hIcon=LoadIcon(AfxGetInstanceHandle(),MAKEINTRESOURCE(IDR_MAINFRAME));
strcpy(tnd.szTip,"提示信息");
Shell_NotifyIcon(NIM_ADD,&tnd);

return 0;
}

void CMainFrame::OnMouseDown(WPARAM wParam,LPARAM lParam)
{
UINT uID;//发出该消息的图标的ID
UINT uMouseMsg;//鼠标动作
POINT pt;
uID=(UINT) wParam;
uMouseMsg=(UINT) lParam;

CMenu *pSubmenu;
if(uMouseMsg==WM_RBUTTONDOWN)
{
switch(uID)
{
case IDI_ONLINE:
GetCursorPos(&pt);
pSubmenu=GetMenu()->GetSubMenu(0);
pSubmenu->TrackPopupMenu(TPM_LEFTALIGN,pt.x,pt.y,AfxGetMainWnd(),NULL);
break;
}
}
if(uMouseMsg==WM_LBUTTONDOWN)
{
switch(uID)
{
case IDI_ONLINE:
GetCursorPos(&pt);
m_menuMy.TrackPopupMenu(TPM_LEFTALIGN,pt.x,pt.y,this);
break;
}
}
return;
}

运行后UID是我自己花的图表的ID
但是任务栏里没有显示啊
怎么回事