C ++ MFC应用程序CMFCBaseTabCtrl选项卡不可见

Question

I have an C++ MFC application created in Visual Studio 2015. I want to add a new tab to the application and created this function in the mainFrame class:

void CMainFrame::OnCustomerNewcustomer()
{
    const CObList &tabGroups = GetMDITabGroups();
    CMFCTabCtrl *wndTab = (CMFCTabCtrl*)tabGroups.GetHead();
    CCustomerList *customer = (CCustomerList*)RUNTIME_CLASS(CCustomerList)->CreateObject();
    ((CWnd*)customer)->Create(NULL, NULL, WS_VISIBLE | WS_CHILD, CRect(0, 0, 20, 20), this, IDD_FORMVIEW_NEW_CUSTOMER);
    wndTab->AddTab(customer, _T("New Customer"), -1, 1);
}

The new tab is showed in the tab controller but if I selecte the tab it does not show the frame in IDD_FORMVIEW_NEW_CUSTOMER it only show the last selected tab's frame. Does anyone know how to fix this?

Answer 1

You are mixing two concepts you should not: MDI Child Windows and the CMFCTabCtrl tabs.

I presume your CMainFrame class is descendant from CMDIFrameWndEx or anything similar. If you want to have a MDI application, you should read more about Document/View architecture.

You will need to have at least one CMultiDocTemplate (or a derived class) object, which will have an association of {Document, Child Frame, View}

Your code on OnInitInstance will look something like:

CYourDocument* pDoc = /*WriteFunctionToGetApplicationDocument*/();
if (!pDoc)
{
    ASSERT(FALSE);
    return FALSE;
}

CMultiDocTemplate* pDocTemplate;

pDocTemplate = new CMultiDocTemplate(IDR_YOUR_DOCUMENT_TYPE,
    RUNTIME_CLASS(CYourDocument),
    RUNTIME_CLASS(CYourChildFrame),
    RUNTIME_CLASS(CYourView));

if (!pDocTemplate)
{
    CoUninitialize();   // if you did CoInitailize before   
    return FALSE;
}
AddDocTemplate(pDocTemplate);

In the procedure you want to add a new tab, refer to that template and instruct to create the respective frame:

 CYourChildFrame* pFrame = NULL;

 // add code to see pFrame is already open

if (!pFrame)
{
    CWaitCursor wc;

    CDocTemplate* pDocTemplate = /*WriteFunctionToGetApplicationMultiDocTemplate*/();
    if (!pDocTemplate)
    {
        ASSERT(FALSE);
        return;
    }

    pFrame = dynamic_cast<CYourFrame*>(pDocTemplate->CreateNewFrame(pDoc, NULL));
    if (!pFrame)
    {
        ASSERT(FALSE);
        return;
    }

    pDocTemplate->InitialUpdateFrame(pFrame, pDoc);
}

if (pFrame)
    MDIMaximize(pFrame);