问题类如下:
class CUserFrame : public CMDIChildWnd
调用函数如下,实现功能是只能生成一个子框架和视图:
void CDatamartApp::OnUserManagement()
{
extern CUserFrame * bUserManagement;
if(!bUserManagement)
{
CMainFrame* pFrame = STATIC_DOWNCAST(CMainFrame, m_pMainWnd);
bUserManagement=(CUserFrame *)pFrame->CreateNewChild(RUNTIME_CLASS(CUserFrame), IDR_MAINFRAME, m_hMDIMenu, m_hMDIAccel);
}
else
{
bUserManagement->SendMessage(WM_SETFOCUS);
}
}
程序运行后,只要调用OnUserManagement(),跟踪器就出现:
Warnning: no shared menu/acceltable for MDI Child window.
经过追踪,发现问题是winmdi.cpp中以下函数(红色部分)导致的:
BOOL CMDIChildWnd::LoadFrame(UINT nIDResource, DWORD dwDefaultStyle,
CWnd* pParentWnd, CCreateContext* pContext)
{
// only do this once
ASSERT_VALID_IDR(nIDResource);
ASSERT(m_nIDHelp == 0 || m_nIDHelp == nIDResource);
m_nIDHelp = nIDResource; // ID for help context (+HID_BASE_RESOURCE)
// parent must be MDI Frame (or NULL for default)
ASSERT(pParentWnd == NULL || pParentWnd->IsKindOf(RUNTIME_CLASS(CMDIFrameWnd)));
// will be a child of MDIClient
ASSERT(!(dwDefaultStyle & WS_POPUP));
dwDefaultStyle |= WS_CHILD;
// if available - get MDI child menus from doc template
CMultiDocTemplate* pTemplate;
if (pContext != NULL &&
(pTemplate = (CMultiDocTemplate*)pContext->m_pNewDocTemplate) != NULL)
{
ASSERT_KINDOF(CMultiDocTemplate, pTemplate);
// get shared menu from doc template
m_hMenuShared = pTemplate->m_hMenuShared;
m_hAccelTable = pTemplate->m_hAccelTable;
}
else
{
TRACE(traceAppMsg, 0, "Warning: no shared menu/acceltable for MDI Child window.\n");
// if this happens, programmer must load these manually
}
CString strFullString, strTitle;
if (strFullString.LoadString(nIDResource))
AfxExtractSubString(strTitle, strFullString, 0); // first sub-string
ASSERT(m_hWnd == NULL);
if (!Create(GetIconWndClass(dwDefaultStyle, nIDResource),
strTitle, dwDefaultStyle, rectDefault,
(CMDIFrameWnd*)pParentWnd, pContext))
{
return FALSE; // will self destruct on failure normally
}
// it worked !
return TRUE;
}
请问怎么会这样?