COM unable to obtain interface -

act_x

I have some COM client code that I am trying to write

IAdd \*pAdd = NULL ; 
IClassFactory \*pClassFactory= NULL  ; 
IUnknown \*pUnknown = NULL ; 

if (SUCCEEDED(CoInitializeEx(NULL, COINIT\_APARTMENTTHREADED)))
{
	HRESULT res = CoCreateInstance(g\_MotAutoplaycfgCLSID , NULL , CLSCTX\_ALL   , IID\_IUnknown , (void \*\*)&pUnknown);
	//res = pUnknown->QueryInterface(IID\_IAdd , (void \*\*)pAdd);

	 res = CoGetClassObject(g\_MotAutoplaycfgCLSID , CLSCTX\_ALL , NULL , IID\_IClassFactory , (void \*\*)pClassFactory );
	if(res == E\_NOINTERFACE )
	{
		int x = 1; 
	}
	else if(res == E\_INVALIDARG)
	{
		int r = GetLastError() ; 
	}
}

I can get this to retrive a valid pointer for pUnknown

	HRESULT res = CoCreateInstance(g\_MotAutoplaycfgCLSID , NULL , CLSCTX\_ALL   , IID\_IUnknown , (void \*\*)&pUnknown);

However I am unable to obtain the interface Handle to IAdd Interface. On the Server Side I can see that the ClassFactory class is created and that the Coclass is also instantiated. Help is appreciated

Engineering is the effort !

Tarmo Kalda

You can use pUnknown->QueryInterface(.. , IAdd, ....) Tarmo.

CPallini

What is the error you get?

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

act_x

I was able to modify my client code to do this

if (SUCCEEDED(CoInitializeEx(NULL, COINIT_APARTMENTTHREADED)))
{

	HRESULT  res = CoGetClassObject(g\_MycfgCLSID , CLSCTX\_ALL , NULL , IID\_IClassFactory , (void \*\*)&pClassFactory );

	if(SUCCEEDED(res))
	{
		// res  = pUnknown->QueryInterface(IID\_IAdd,(void \*\*)&pAdd);
		res = pClassFactory->CreateInstance(0,IID\_IAdd , (void \*\*)&pAdd);
		pClassFactory->Release(); 
	}
	else if(res == E\_NOINTERFACE )
	{
		int x = 1; 
	}
	else if(res == E\_INVALIDARG)
	{
		int r = GetLastError() ; 
	}
	CoUninitialize(); 
}

The call to

HRESULT res = CoGetClassObject(g_MycfgCLSID , CLSCTX_ALL , NULL , IID_IClassFactory , (void **)&pClassFactory );

succeeds providing a pointer to IClassFactory However this line

res = pClassFactory->CreateInstance(0,IID_IAdd , (void **)&pAdd);

returns the following error

#define REGDB_E_IIDNOTREG _HRESULT_TYPEDEF_(0x80040155L)

Engineering is the effort !

CPallini

It states the class you're asking for is not registered. :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke