[Resolved] Character String -> Wide Character String conversion problems

[Evil_Giraffe]

Trying to use the StgCreateDocfile or StgOpenStorage functions, MSDN says the first parameter, pwcsName, should point to the path of the file containing the storage object. I use the following code to get the filename of an existing file:

OPENFILENAME ofn;
ZeroMemory(&ofn, sizeof(ofn));
ofn.lStructSize = sizeof(ofn);			// OS specific - may need to change for different Windows versions
ofn.hwndOwner = hwnd;
ofn.lpstrFilter = "Word Documents (*.doc)\0*.doc\0All files (*.*)\0*.*\0";
ofn.lpstrFile = szFileName;
ofn.nMaxFile = MAX_PATH;
ofn.Flags = OFN_EXPLORER | OFN_FILEMUSTEXIST | OFN_HIDEREADONLY;
ofn.lpstrDefExt = "doc";
if (GetOpenFileName(&ofn))
{
	// Do something with the file name
...

Then, since I need it in Wide Character String format, I do the following:

MessageBox(NULL, szFileName, "", MB_OK);  // Debugging purposes - supplies correct filename, e.g "C:\My Documents\test.doc"
CharsConverted = mbstowcs(wcsFileName, szFileName, NULL);

This I *assume* has converted correctly, since I can't figure out how to view the contents of it in Debug mode
So, I try to open this storage file:

hresFile = StgOpenStorage(wcsFileName, NULL, grfDocFileFlags, NULL, 0, ppstgDocFile);

But this returns STG_E_INVALIDNAME in hresFile:

STG_E_INVALIDNAME
Indicates bad name in the pwcsName parameter.

Any ideas what I'm doing wrong?

Thanks

Chris

[Edit: Okay, i got it now. Stupid stupid me:

CharsConverted = mbstowcs(wcsFileName, szFileName, NULL);

should be:

CharsConverted = mbstowcs(wcsFileName, szFileName, MAX_PATH);

I thought NULL would mean carry on until you get to the end, but it's just an alias for /0, so it converted no characters ]