IUnknown interface

Look-up the functions CoCreateIntance, CocreatetInstanceEx and QueryInterface. I'm not at home so I don't have an example off the top of my head.

You may have to change the code to get the Music interfaces second, instead of getting them from the directx objects indirectly.

general steps:

1)Use CocreatetInstanceEx and a pointer to Iunknown to create the music object, save this iunknown for later.
2)Use Iunknown and queryinterface to make the music interfaces
3)you can now use iunknown to stop the music.

BUT also see if the music interfaces have QueryInterface built in already. Then you just call QueryInterface on the Music interfaces to get Iunknown...

hope that helps and take the advice with a grain of salt.. going on memory...



Edited by - choff on January 7, 2002 10:02:44 AM

Thanks loads choff, Ive got it now.

As you suggest I can get the IUnknown interface pointer using:

Hr = g_pSegment->QueryInterface(IID_IDirectMusicSegment8, (LPVOID*)&pObjectToStop);

and pObjectToStop works with the SopEx method.

Thanks again,

henry

IUnknown is the base class for all COM objects, so there is no reason to query for it. Just pass the object pointer and the compiler should handle it.

Jim

Jim is correct. IDirectMusicSegment8 and IDirectMusicSegmentState both inherit from IUnknown (as do all DirectX interfaces) and are therefor subtypes of IUknown. This means they can be passed to any parameter that takes an IUknown object.

- Kaijin