How to get CLSID for the underlying object.

[cagey]

I have a COM interface and would like the CLSID for the underlying implementing object. The interface I have decends from IDispatch, and I have played with ITypeInfo. I am able to get the IID of the interface, but not the CLSID of the object. Is there an easy way to do this? Thanks, cagey

[soptest]

In order to get CLSID of running COM instance that object must have at least IPersist to be implemented. --or-- To read CLSID from TypeLib (If you TypeLib has more then one coclass and some of those coclasses have implemented the same interface you can not say which coclass is instantiated):

#include #include #include "comdef.h"
#include "atlbase.h"

void main()
{
CoInitialize(0);
{
CComPtr p;
HRESULT hr;

	hr = p.CoCreateInstance(L"TestObj.Test");
	if(S\_OK == hr)
	{
		
		::ITypeInfo \*pti;
		::ITypeLib \*ptl;
		UINT ui;

		hr = p->GetTypeInfo(0, LOCALE\_SYSTEM\_DEFAULT,&pti);
		
		if(S\_OK == hr)
		{
			hr = pti->GetContainingTypeLib( &ptl, &ui);
			pti->Release();
			if(S\_OK == hr)
			{
				ui = ptl->GetTypeInfoCount();
				
				for(UINT i = 0; i < ui; ++i)
				{
					hr = ptl->GetTypeInfo(i, &pti);
					
					
					if(S\_OK == hr)
					{
						
						::TYPEATTR \*patr = 0;
						hr = pti->GetTypeAttr( &patr);
						if(patr->typekind == TKIND\_COCLASS)
						{
							printf("OK - TKIND\_COCLASS\\n");
							OLECHAR \*wsz;
							hr = ::StringFromCLSID(patr->guid, &wsz);
							
							if(S\_OK == hr)
							{
								printf("CLSID = %s\\n",(char\*) \_bstr\_t(wsz));
								::CoTaskMemFree(wsz);
							}
						}
						pti->Release();
					}
				}
				ptl->Release();
				
			}
		}
	}
}
CoUninitialize();

}

soptest

[Gertjan Schuurmans]

soptest's code should be working in most cases, but first check if the object supports IPersist, IProvideClassInfo or IProvideClassInfo2. You can then obtain the class ID in a very simple way through: IPersist::GetClassID() IProvideClassInfo2::GetGUID() gertjan