Thread: Failing to initialize COM

Alright so I am attempting to initialize direct music via the COM interface exactly as it appears on MSDN. My function looks like this:

Code:

HRESULT CDirectX::initDirectSound (HWND hwnd) {

	_Performance = NULL;
	_Loader = NULL;

	
	CoInitialize(NULL);
		
	CoCreateInstance(CLSID_DirectMusicLoader, NULL, CLSCTX_INPROC, IID_IDirectMusicLoader8, (void**) &_Loader);
	if(_Loader = NULL)
		return E_FAIL;
	
	CoCreateInstance(CLSID_DirectMusicPerformance, NULL, CLSCTX_INPROC, IID_IDirectMusicPerformance8, (void**)& _Performance);
	
	if(_Performance = NULL)
		return E_FAIL;

	_Performance->InitAudio(NULL, NULL, hwnd, DMUS_APATH_SHARED_STEREOPLUSREVERB, 64, DMUS_AUDIOF_ALL, NULL);
	
	_Loader->SetSearchDirectory (GUID_DirectMusicAllTypes, 
		                         L"C:\\Documents and Settings\\Andrew Hunter\\My Documents\\My Music",
								 FALSE );
	return S_OK;
}

The problem is that _Loader never appears to become initialized, aka the program halts and the value of _Loader is NULL. Has anyone seen this before?

I have run the D3D debug and it turns out that Loader is NULL, IDirectMusicPerformance is NULL, IUnknown is null and through the vfptr all values beneath indicate CXX0030:Expression cannot be evaluated.

if(_Loader = NULL)

You're confusing the = and == operators

This sets _Loader to NULL then evaluates whether that's true. Which isn't what you want.

You want

if(_Loader == NULL)

Same applies for the if(_Performance = NULL) line.

I can't believe I did that!!!!! Sometimes I guess you just get to into a project. Thanx plenty.

BTW, an easy way to not use = when you want == is to write (completely equivalently) it like this:

if (NULL == _Loader)

Then if you wrote

if (NULL = _Loader)

you'd get a compiler error, rather than weird behaviour at runtime.

All right I fixed the above mentioned assignment problem (I am an idiot - thx again azteched) unfortunately I am still receiving an error when I attempt to load the file. This is the function I am using:

Code:

if(FAILED(_Loader->LoadObjectFromFile (CLSID_DirectMusicSegment,
										   IID_IDirectMusicSegment8,
										   szfileName,
										   (void**)& _Segment)))
	   return E_FAIL;

Unfortunately the pointers are as described above with null values. _Loader doesn't seem to ever get anything put into it. Any ideas?

Ok it still isn't initializing. this is the line I am using:

Code:

CoCreateInstance(CLSID_DirectMusicLoader, NULL, CLSCTX_INPROC, IID_IDirectMusicLoader8, (void**) _Loader);

Any ideas. The COM object isn't being found I guess?

anonytmouse thank you. I must have dropped it off when I was moving my code around in the source file. Greatly appreciated all. I will try not to be soo stupid in the future.