Re: can access resource library from main .exe but not loaded .dll

I have a library MyLib.dll, which I am testing via a test
program
TestProgram.exe.
TestProgram.exe is an ATL app which statically links to
MyLib.dll.

MyLib.dll requires some resources in MyRes.dll, so, before
calling any
routines in MyLib.dll, TestProgram.exe first loads the
MyRes.dll
resource library.

The code to do so:

****************** CODE START ******************

static LPCTSTR gsResourceDLL = _T("MyRes.dll");
HRESULT CMainDlg::LoadResourceDLL()
{
// Load Resource DLL
TCHAR lpszLocFileName[_MAX_PATH];
GetModuleFileName( _AtlBaseModule.GetModuleInstance(),
lpszLocFileName, _MAX_PATH);
PathRemoveFileSpec(lpszLocFileName);
_tcscat( lpszLocFileName, _T("\\") );
_tcscat( lpszLocFileName, gsResourceDLL);

HMODULE hm = LoadLibrary( lpszLocFileName );

if ( hm == 0 )
{
return S_FALSE;
}

HINSTANCE hThisModule =
_AtlBaseModule.GetModuleInstance();
_AtlBaseModule.AddResourceInstance(hm);

return S_OK;
}

****************** CODE END ******************

I can verify that the library is correctly loaded via the
following
test routine, which just attempts to find and lock a
particular
resource in the resource library:

****************** CODE START ******************

void TestResource(LPCTSTR lpszResourceName)
{
LPVOID lpResource = NULL;
HGLOBAL hResource = NULL;
HRSRC hDlgInit = NULL;

int i = 0;
HINSTANCE hInst = _AtlBaseModule.GetHInstanceAt(i);
while(hInst != NULL)
{
WORD wLanguage = 0;
hDlgInit = ::FindResourceEx(hInst, RT_HTML,
ATL::CW2CT(lpszResourceName), wLanguage);
if (hDlgInit != NULL)
break;

//get next
hInst = _AtlBaseModule.GetHInstanceAt(i++);
}

if (hDlgInit != NULL)
{
// load it
hResource = ::LoadResource(hInst, hDlgInit);
if (hResource == NULL)
return;

// lock it
lpResource = ::LockResource(hResource);
_ASSERT(lpResource != NULL);
}

//do something with the resource...

// cleanup
if (lpResource != NULL && hResource != NULL)
{
UnlockResource(hResource);
FreeResource(hResource);
}
}

****************** CODE START ******************

However, when MyLib.dll tries to access the same resource
in the exact
same way, it fails to find it (FindResourceEx never finds
anything and
always returns NULL).

What is going on?

If I add the load library code to MyLib.dll and run it
from
TestProgram.exe, then MyLib.dll can find resources in
MyRes.dll...

Why is this necessary? Why can't MyRes.dll see resources
loaded by and
available to TestProgram.exe? They use the same handles
for the
resource as far as I can tell...

Thanks in advance for any help you can provide.