Converting HTML resource to string in MFC-CodePudding

I get jargons while converting HTML resource to CString in an MFC application. Any help will be appreciated. I am compiling on VC 2022, obviously with unicode.

CString GetHTML(const int& RESOURCE_ID)
{
    CString str;
    HRSRC hrsrc = FindResource(NULL, MAKEINTRESOURCE(RESOURCE_ID), RT_HTML);
    if (hrsrc != NULL)
    {
        HGLOBAL pResource = LoadResource(NULL, hrsrc);
        if (pResource != NULL)
        {
            LPCTSTR lpctstr = static_cast<LPCTSTR>(LockResource(pResource));
            if (lpctstr != NULL)
            {
                str = CString(lpctstr, ::SizeofResource(NULL, hrsrc));
                return str;
            }
            UnlockResource(pResource);
        }
        FreeResource(pResource);
    }
    return NULL;
}

CodePudding user response：

My psychic powers suggest that the your HTML resource file is ascii, but you are casting the ascii bytes returned by LockResource to be a unicode string LPCTSTR (pointer to TCHAR).

Simplest approach would be to have your function return a CStringA instead of a CStringW and do all your processing on the string as ascii.

Declare your function to return a CStringA instance explicitly:

CStringA GetHTML(const int& RESOURCE_ID)
{
    CStringA str;

Then, instead of this:

        LPCTSTR lpctstr = static_cast<LPCTSTR>(LockResource(pResource));
        if (lpctstr != NULL)
        {
            str = CString(lpctstr, ::SizeofResource(NULL, hrsrc));
            return str;
        }

This:

        const char* psz = static_cast<const char*>(LockResource(pResource));
        if (psz != NULL)
        {
            str = CStringA(psz);
            return str;
        }

Alternatively, if you want to return a unicode CString(W) from your function, you could convert the resource to unicode using MultiByteToWideChar API. MFC/ATL provides a convenient macro for doing this.

        const char* psz = static_cast<const char*>(LockResource(pResource));
        if (psz != NULL)
        {
            USES_CONVERSION;
            CStringW strW = A2W(psz);
            return strW;
        }

Also, notice that I removed all LPCTSTR references. I have numerous rants about avoiding TCHAR macros.