"No such interface supported" when activating CDS

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7 total messages Started by Denis Pyr Tue, 07 Mar 2000 00:00

#1166

Author: Denis Pyr
Date: Tue, 07 Mar 2000 00:00

31 lines
1574 bytes

Hi all
I followed the steps described in C++Builder Unleashed, in order to
create a simple MIDAS server and client. In brief, the steps I took
were
For the server
S1/ Create new application
S2/ Add a Remote DataModule
S3/ Add a TDatabase, a TQuery and a TTable, set them up (they point to
the employee.db file), then activate them
S4/ Make the SERVER.EXE, then run it: SERVER /RegServer
For the client
C1/ Create new application
C2/ Add a RemoteServer, set the RemoteServer property (selected
through the combo), activate it
C3/ Add a ClientDataSet, connect it to the remote server, connect it
to the remote dataset (I see both query andtable in the combo)
C4/ Try to activate the CDS. I receive the following message

'src->QueryInterface(GetID(), (LPVOID*)(&intf))': No such interface
supported
@D:\DEVTOOLS\BCB4\INCLUDE\VCL\utilcls.h/2014
Yes, No, Cancel

and, off course, I cannot connect.

Hm!?!? Any ideas?

TIA

PS A search on deja return many messages but I cannot see any - "Local
server error" it says :(

Re: "No such interface supported" when activating CDS

#1167

Author: Helmut Hahn
Date: Tue, 07 Mar 2000 00:00

10 lines
823 bytes

Hi,

did you install the Patch #1? If yes unisntall and reinstall BCB4.0 and
see if it works.
I had the same problems, but the above did help. I would like to hear from
you if you have
the same behavior.

Thanks
Helmut

Re: "No such interface supported" when activating CDS

#1168

Author: Denis Pyr
Date: Thu, 09 Mar 2000 00:00

16 lines
1045 bytes

Hi Helmut

On Tue, 07 Mar 2000 19:27:56 +0100, Helmut Hahn <helmut.hahn@tmt.de>
wrote:

>did you install the Patch #1? If yes unisntall and reinstall BCB4.0 and
>see if it works.

Of course I did install P#1 :)
You mean, reinstall BCB *without* installing the patch?

>I had the same problems, but the above did help. I would like to hear from
>you if you have
>the same behavior.

I' let you know as soon as I do it.

Re: "No such interface supported" when activating CDS

#1169

Author: Denis Pyr
Date: Fri, 10 Mar 2000 00:00

13 lines
1239 bytes

Hi Helmut

unfortunatelly, I verify that the malfunction is caused by the patch.
I did the simple server/client pair using unpatched and patched BCB4.
The "patched" server is causing the exception while the "unpatched"
one is OK.
Now, one solution is to unistall BCB and reinstall it each time I want
to build a server.
BCB5 being on the road, the only way out is to buy that version :(

PS what strikes me is the question "NOBODY uses midas"? I mean, this
is too obvious for anybody to miss it. Midas is practically unusable
if one uses the latest version of Builder.

Re: "No such interface supported" when activating CDS

#1175

Author: Harold Howe (TeamB)
Date: Mon, 13 Mar 2000 00:00

23 lines
1235 bytes

Denis Pyr wrote in message ...
>Hi Helmut
>
>unfortunatelly, I verify that the malfunction is caused by the patch.

This has been covered before. You need to alter the code on the server side
that exports the provider. Find the function where the provider is exported
and change:

  *Value = IProv;

to

  *Value = (IProvider *)IProv;

Also change all occurrences of IProvider ** to IProviderPtr *.

PS: this is only problem when converting code that was generated with
pre-patch BCB4 to post-patch BCB4.

Harold Howe [TeamB]
http://www.bcbdev.com

Re: "No such interface supported" when activating CDS

#1178

Author: Denis Pyr
Date: Tue, 14 Mar 2000 00:00

17 lines
1282 bytes

Hi Harold

thanks for the feedback. I've also been noticed about the article
10305 which describes the solution.
I have to disagree with your PS. When I originally stated the problem,
I had no idea about pre- and post- patched alternatives. The problem
occurs to a fresh project as well.

BTW thanks for the great bcbdev.com

On Mon, 13 Mar 2000 15:35:40 -0600, "Harold Howe (TeamB)"
<hhowe@bcbdev.com> wrote:

<snip>

>PS: this is only problem when converting code that was generated with
>pre-patch BCB4 to post-patch BCB4.

Re: "No such interface supported" when activating CDS

#1179

Author: Harold Howe (TeamB)
Date: Tue, 14 Mar 2000 00:00

34 lines
1544 bytes

>>PS: this is only problem when converting code that was generated with
>>pre-patch BCB4 to post-patch BCB4.
>
>I have to disagree with your PS. When I originally stated the problem,
>I had no idea about pre- and post- patched alternatives. The problem
>occurs to a fresh project as well.

It looks like the post-patch version generates code that *correctly* uses
IProviderPtr, but forgets to add the cast in the assignment to Value.

STDMETHODIMP TMidasTestImpl::get_Query1(IProviderPtr* Value)
{
  try
  {
  _di_IProvider IProv = m_DataModule->Query1->Provider;
  IProv->AddRef();
  *Value = IProv;   // missing cast here
  }
...
};

Do you agree?



>BTW thanks for the great bcbdev.com


Thank you, and you're welcome.


Harold Howe [TeamB]
http://www.bcbdev.com

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