C / C++ / MFC

LPSHELLFOLDER pDesktopFolder;
::SHGetDesktopFolder(&pDesktopFolder);

LPSHELLFOLDER psfFolder = NULL;
LPITEMIDLIST pFolderPIDL = ::ILCreateFromPath(lpszPath);
HRESULT hRes = pDesktopFolder->BindToObject(
    pFolderPIDL,
    NULL,
    IID_IShellFolder,
    IID_PPV_ARGS(&psfFolder)
);

// Example to get the PIDL of a named file or folder within a folder
// This PIDL can then be used for other IShellFolder operations
LPITEMIDLIST pPIDL;
CString strName; // name within folder
hRes = psfFolder->ParseDisplayName(
    NULL,		 // no hWnd necessary when showing no dialog
    NULL,		 // no bind context
    strName.GetBuffer(), // non-const LPWSTR
    NULL,		 // no need to get number of parsed characters
    &pPIDL,		 // PIDL relative to the parsing folder
    NULL		 // attributes not used
);
strName.ReleaseBuffer();

// Releasing
::CoTaskMemFree(pPIDL);
psfFolder->Release();
::ILFree(pFolderPIDL);
pDesktopFolder->Release();

ForNow wrote:

I don’t specify __declspec(dllimport)

// The following ifdef block is the standard way of creating macros which make exporting 
// from a DLL simpler. All files within this DLL are compiled with the WIN32PROJECT2_EXPORTS
// symbol defined on the command line. This symbol should not be defined on any project
// that uses this DLL. This way any other project whose source files include this file see 
// WIN32PROJECT2_API functions as being imported from a DLL, whereas this DLL sees symbols
// defined with this macro as being exported.
#ifdef WIN32PROJECT2_EXPORTS
#define WIN32PROJECT2_API __declspec(dllexport)
#else
#define WIN32PROJECT2_API __declspec(dllimport)
#endif

// This class is exported from the Win32Project2.dll
class WIN32PROJECT2_API CWin32Project2 {
public:
	CWin32Project2(void);
	// TODO: add your methods here.
};

extern WIN32PROJECT2_API int nWin32Project2;

WIN32PROJECT2_API int fnWin32Project2(void);

Many export directives, such as ordinals, NONAME, and PRIVATE, can be made only in a .def file, and there is no way to specify these attributes without a .def file. However, using __declspec(dllexport) in addition to using a .def file does not cause build errors.

HKEY hKey;
DWORD dwResult = RegOpenKeyEx(HKEY_CURRENT_USER, nullptr, 0, KEY_READ, &hKey);
if (ERROR_SUCCESS == dwResult)
{
    std::wstring subkey = L"Software\\Microsoft\\Windows\\CurrentVersion\\Run";
    std::wstring value = L"OneDrive";
    RegGetString(hKey, subkey, value);
}
RegCloseKey(hKey);

Richard Andrew x64 wrote:

I notice that you opened the HKEY without specifying a subkey in the call to RegOpenKeyEx. You only specified the subkey in the call to RegGetString. Is that the way it's supposed to work? Should I not pass a subkey to RegOpenKeyEx?

HKEY hKey;
DWORD dwResult = RegOpenKeyEx(HKEY_CURRENT_USER, L"Software\\Microsoft\\Windows\\CurrentVersion\\Run", 0, KEY_READ, &hKey);
if (ERROR_SUCCESS == dwResult)
{
    std::wstring subkey = L"Software\\Microsoft\\Windows\\CurrentVersion\\Run";
    std::wstring value = L"OneDrive";
    RegGetString(hKey, subkey, value);
}
RegCloseKey(hKey);

inline std::wstring RegGetString(HKEY hKey, const std::wstring& subKey, const std::wstring& value)
{
	//
	// Request the size of the string, in bytes
	//
	DWORD dataSize{};
	LONG retCode = ::RegGetValue(
		hKey,
		nullptr, //NULL POINTER ... NOT AN EMPTY STRING
		value.c_str(),
		RRF_RT_REG_SZ,
		nullptr,
		nullptr,
		&dataSize);
	if (retCode != ERROR_SUCCESS)
	{
		int iDebug = 0;
	}
	return L"";
}