ATL / WTL / STL

21-Dec-08 19:59

I have aggregated IID_IInner and IID_IEnumVARIANT as follows

COM_INTERFACE_ENTRY_AGGREGATE(IID_IInner, m_pInnerUnk)
COM_INTERFACE_ENTRY_AGGREGATE(IID_IEnumVARIANT, m_pInnerUnk)

How do i call CoCreateInstance(...) in FinanConstruct() method?

Re: COM aggregation

Stuart Dootson22-Dec-08 0:49

Doubt in QueryInterface pointers

22-Dec-08 0:49

This page[^] gives an example.

KASR121-Dec-08 18:45

Re: Doubt in QueryInterface pointers

21-Dec-08 18:45

//
IEP_SimpleObjPtr pEP_SimpleObj1;
pEP_SimpleObj1.CreateInstance(__uuidof(EP_SimpleObj));

IEP_SimpleObj1Ptr pEP_SimpleObj2;
pEP_SimpleObj1->QueryInterface(__uuidof(IEP_SimpleObj2), (void**) &pEP_SimpleObj2);

pEP_SimpleObj2->Release();
//

In the above code I have released pEP_SimpleObj2 pointer.
But still I can call methods using pEP_SimpleObj2 pointer. How?

Stuart Dootson22-Dec-08 0:46

Re: Doubt in QueryInterface pointers

22-Dec-08 0:46

As the object is also referenced by pEP_SimpleObj1, Releasing pEP_SimpleObj2 will probably only decrease the object's reference count to 1, so the object will still exist. If pEP_SimpleObj2 is just pointing within the object pointed at by pEP_SimpleObj1 (highly likely), then so long as the address held in pEP_SimpleObj2 hasn't changed, the pointer will still point at valid memory.

The point is that you cannot rely on this behaviour - it is NOT guaranteed. So don't do it.

Also - the whole point of managed pointers is that you don't need to bother with AddRef and Release - let the pointer objects do that for you in their constructors/destructors.

KASR122-Dec-08 0:51

cannot open include file 'atlres.h'

22-Dec-08 0:51

Yes we don't need to release managed pointers.
I tried to check how released pointers will work.
Its clear now. Thanks for your explanation.

josip cagalj19-Dec-08 1:53

19-Dec-08 1:53

Hi to all. I'm trying to open some project wroted using WTL. When I try to rebuild it (using VS2008 on Win XP) I get the compile error as above. Now, "atlres.h" file is in directory which I added to my project settings properly and I don't know why error appears!?
The message states "cannot open.." which means it has no trouble locating it? but rather cant open it?
Please help!
Thanks in advance.

Stuart Dootson19-Dec-08 2:16

19-Dec-08 2:16

I think you need to add the WTL include directory to the include directory path for the resource compiler. Right-click on the project, select 'Properties', select Resources->General in the properties window and add the WTL include directory to Additional Include Directories.

josip cagalj19-Dec-08 2:35

19-Dec-08 2:35

Thanks for replaying to me. I already have directory path (D:\...\WTL80\include) included in Aditional Include Directories.
?

Stuart Dootson19-Dec-08 2:38

19-Dec-08 2:38

In the Additional Include Directories for the resource compiler? I'm NOT talking about the C++ compiler options...

josip cagalj19-Dec-08 2:42

19-Dec-08 2:42

In 'MyProgram' Property Pages under C/C++ General Additional Include Directories.

josip cagalj19-Dec-08 2:47

19-Dec-08 2:47

OK I got you.
Stop complaining about that.
Thanks big time!
Now I get:
"fatal error LNK1104: cannot open file 'C:/Program Files/Microsoft SDKs/Windows/v5.0/Lib/DnsAPI.Lib'" ?

Stuart Dootson19-Dec-08 3:05

19-Dec-08 3:05

That's a completely different matter - if you really need DNSAPI.lib, what I'd do is open a Command Prompt window, and execute the following commands:

CD /d "c:\Program Files"
dir /s/b dnsapi.lib

It might take a while to run, probably, but it'll likely find any DNSAPI.lib you have. On my machine, I get the following output:

C:\Program Files\Microsoft SDKs\Windows\v5.0\Lib\IA64\DnsAPI.Lib
C:\Program Files\Microsoft SDKs\Windows\v6.0A\Lib\DnsAPI.Lib
C:\Program Files\Microsoft SDKs\Windows\v6.0A\Lib\x64\DnsAPI.Lib
C:\Program Files\Microsoft SDKs\Windows\v6.1\Lib\DnsAPI.Lib
C:\Program Files\Microsoft SDKs\Windows\v6.1\Lib\IA64\DnsAPI.Lib
C:\Program Files\Microsoft SDKs\Windows\v6.1\Lib\x64\DnsAPI.Lib
C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\PlatformSDK\Lib\DnsAPI.Lib
C:\Program Files\Microsoft Visual Studio 8\VC\PlatformSDK\Lib\DnsAPI.Lib
C:\Program Files\Microsoft Visual Studio 8\VC\PlatformSDK\Lib\AMD64\DnsAPI.Lib

You can see that (for some reason - I don't know why!) I only have Itanium libraries under C:\Program Files\Microsoft SDKs\Windows\v5.0.

josip cagalj19-Dec-08 3:13

19-Dec-08 3:13

Is there any way you can get him to take another one, like second from v6.0A for example?

Stuart Dootson19-Dec-08 3:38

19-Dec-08 3:38

Yes - in the project properties, under 'Linker', you can tell the linker what directories to look in.

Alternatively, you can add them under Tools->Options, somewhere near the place where you can say what C++ include directories to use.

josip cagalj19-Dec-08 3:57

19-Dec-08 3:57

Tried it in both places but still no improvement (in tools options even when I pull it up at the top of list)!
Error:"fatal error LNK1104: cannot open file 'C:/Program Files/Microsoft SDKs/Windows/v5.0/Lib/DnsAPI.Lib'"
But big thanks for you anyway.

Stuart Dootson19-Dec-08 4:16

19-Dec-08 4:16

Sounds like something has the whole of that path hard-coded.

There might (might!) be a #pragma comment(lib, "C:/Program Files/Microsoft SDKs/Windows/v5.0/Lib/DnsAPI.Lib") somewhere in your code or the code you #include?

josip cagalj21-Dec-08 22:59

21-Dec-08 22:59

I agree it looks like hard-coded line of code because no meter what directory path I add, both in 'project property->linker->additional library directories' or 'tools->options->VC++directories(under library files)' I'm getting the same error:
"LINK: fatal error LNK1104: cannot open file 'C:/Program Files/Microsoft SDKs/Windows/v5.0/Lib/DnsAPI.Lib'"!
But can't find where in my code I'm doing that. I inherited this project from another person and on his machine everything works just fine.
???

josip cagalj22-Dec-08 0:08

22-Dec-08 0:08

Problems are solved, I get the project working!
Thanks for helping me around!
If I have any future question al be sure to post it here.
Once again thanks!

Binni shah10-Feb-09 17:17

Binni shah

10-Feb-09 17:17

I am facing the same problem u faced..but i am not getting the solution.
the error i got is:
fatal error LNK1104: cannot open file 'C:/Program Files/Microsoft SDKs/Windows/v5.0/Lib/DnsAPI.Lib'

please help me..
thanks in advance..

josip cagalj11-Feb-09 0:14

11-Feb-09 0:14

Hi,
it was a long time ago, but if I remember correctly I had to recreate the workarounds (folder states/names/positions) as the person who redistrict this project to me. For example I placed all folders needed in my 'D:\MyProject\...' while on his PC it was placed on 'C:\' drive each folder for himself. I know this may seem odd (especially if you link everything properly ) but it worked.
The thing was there was many files to edit and rebuild for things to work this seamed to be the easy way!
Best luck to you!

Life time of COMObject

KASR118-Dec-08 23:51

Re: Life time of COMObject

18-Dec-08 23:51

CComObject<CMyCircle> *pCircle;
HRESULT hRes = CComObject<CMyCircle>::CreateInstance(&pCircle);

IMyCirclePtr pCircle1;
pCircle1.CreateInstance(__uuidof(MyCircle));

Difference between pCircle & pCircle1?

Stuart Dootson19-Dec-08 0:27