Question

I have written a runtime-created dialog class that doesn’t use any resource files based on this example: http://blogs.msdn.com/b/oldnewthing/archive/2005/04/29/412577.aspx

It is compiled on a Windows 7 x64 machine, but as an x86 application. The dialog is part of a larger program that at other places use normal dialogs with resource files (MFC).

The dialog is launched by DialogBoxIndirectParam like this:

DialogBoxIndirectParam(NULL, m_template.GetTemplate(), NULL, DlgProc, reinterpret_cast<LPARAM>(this));

The dialog shows fine on all Windows 7 x64 machines I have tried, but it doesn’t work on Windows XP x86 machines. I don’t know if it’s the Windows version or the CPU bit part that is the culprit.

Some interesting but strange things:

• Dialogs in the same program using normal resources work fine in both Win 7 and Win XP.
• When comparing the runtime-created dialog template byte by byte I can see no difference from the resource-constructed dialogs.
• As long as I don’t add any controls what so ever to the dialog, it WILL display in XP, but if I add as much as a single static it won’t.
• I have monitored the callback function and when it starts it sends WM_SETFONT, WM_DESTROY, WM_NCDESTROY and then dies. It’s like it gives up somewhere between WM_SETFONT and WM_CREATE.

I have found others with similar problems but none exactly like mine: http://social.msdn.microsoft.com/Forums/zh/vcgeneral/thread/45989a10-2785-486d-94ae-4f1f3e1ca651, http://cboard.cprogramming.com/windows-programming/39218-createdialog-failure.html

I must say that I’m at my wits end about this, I’m just not good enough at win32 programming to figure out exactly what could be wrong here.

Here is what the template code looks like:

DialogTemplate::DialogTemplate(const std::wstring& title, WORD width, WORD height) :
m_numControls(0)
{
    AddHeader(title, width, height);
    AddFont();
}

DialogTemplate::~DialogTemplate(void)
{
}

void DialogTemplate::AddHeader(const std::wstring& title, WORD width, WORD height)
{
    // Write out the extended dialog template header
    m_data.Write<WORD>(1); // dialog version
    m_data.Write<WORD>(0xFFFF); // extended dialog template
    m_data.Write<DWORD>(0); // help ID
    m_data.Write<DWORD>(0); // extended style
    m_data.Write<DWORD>(WS_CAPTION | WS_SYSMENU | DS_SETFONT | DS_MODALFRAME);
    m_data.Write<WORD>(0); // number of controls (placeholder)
    m_data.Write<WORD>(32); // X
    m_data.Write<WORD>(32); // Y
    m_data.Write<WORD>(width); // width
    m_data.Write<WORD>(height); // height
    m_data.WriteString(L""); // no menu
    m_data.WriteString(L""); // default dialog class
    m_data.WriteString(title.c_str()); // title
}

bool DialogTemplate::AddFont()
{
    // Write out font
    HDC hdc = GetDC(NULL);
    if (!hdc)
        return false;

    NONCLIENTMETRICSW ncm = { sizeof(ncm) };
    if (!SystemParametersInfoW(SPI_GETNONCLIENTMETRICS, 0, &ncm, 0))
        return false;

    if (ncm.lfMessageFont.lfHeight < 0)
        ncm.lfMessageFont.lfHeight = -MulDiv(ncm.lfMessageFont.lfHeight, 72, GetDeviceCaps(hdc, LOGPIXELSY));

    m_data.Write<WORD>((WORD)ncm.lfMessageFont.lfHeight); // point
    m_data.Write<WORD>((WORD)ncm.lfMessageFont.lfWeight); // weight
    m_data.Write<BYTE>(ncm.lfMessageFont.lfItalic); // Italic
    m_data.Write<BYTE>(ncm.lfMessageFont.lfCharSet); // CharSet
    m_data.WriteString(ncm.lfMessageFont.lfFaceName);

    return true;
}

void DialogTemplate::AddControl(LPCWSTR pszType, WORD x, WORD y, WORD width, WORD height, const std::wstring& text, DWORD controlId, DWORD style)
{
    m_data.AlignToDword();
    m_data.Write<DWORD>(0); // help id
    m_data.Write<DWORD>(0); // window extended style
    m_data.Write<DWORD>(WS_CHILD | style); // style
    m_data.Write<WORD>(x); // x
    m_data.Write<WORD>(y); // y
    m_data.Write<WORD>(width); // width
    m_data.Write<WORD>(height); // height
    m_data.Write<DWORD>(controlId); // control ID
    m_data.WriteString(pszType);    // control type (as string)
    m_data.WriteString(text.c_str()); // text
    m_data.Write<WORD>(0); // no extra data

    ++m_numControls;
    m_data.Overwrite<WORD>(m_numControls, NUM_CTRL_OFFS);
}

void DialogTemplate::AddControl(DWORD dwType, WORD x, WORD y, WORD width, WORD height, const std::wstring& text, DWORD controlId, DWORD style)
{
    m_data.AlignToDword();
    m_data.Write<DWORD>(0); // help id
    m_data.Write<DWORD>(0); // window extended style
    m_data.Write<DWORD>(WS_CHILD | style); // style
    m_data.Write<WORD>(x); // x
    m_data.Write<WORD>(y); // y
    m_data.Write<WORD>(width); // width
    m_data.Write<WORD>(height); // height
    m_data.Write<DWORD>(controlId); // control ID
    m_data.Write<DWORD>(dwType);    // control type (as DWORD)
    m_data.WriteString(text.c_str()); // text
    m_data.Write<WORD>(0); // no extra data

    ++m_numControls;
    m_data.Overwrite<WORD>(m_numControls, NUM_CTRL_OFFS);
}

Wow, it’s super annoying to paste code here if it’s indented by tabs :-/

Answer 1

The code looks about right, but it does not show the produced template, which fails to instantiate.

One thing I noticed weird is:

m_data.Write<DWORD>(dwType);    // control type (as DWORD)

This does not sound about right, you need 0xFFFF in front if it:

If the first element is 0xFFFF, the array has one additional element
that specifies the ordinal value of a predefined system class. The
ordinal can be one of the following atom values.