C / C++ / MFC

Any samples for inserting an image into a BLOB field of a DB2 table using VC++ 6.0?

19-Jun-02 8:09

Use the aforementioned Spy++ utility to see what message(s) get sent to it when it is closed from the context menu.

Peace!

-=- James.
"Some People Know How To Drive, Others Just Know How To Operate A Car."
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Shayna19-Jun-02 5:27

Shayna

19-Jun-02 5:27

Anyone has any sample code for inserting an image into a BLOB field of a DB2 table using VC++ 6.0?

Please help. Cry | :((

Retreiving BSTR

Hans Ruck19-Jun-02 5:09

Hans Ruck

19-Jun-02 5:09

I use this:

STDMETHODIMP CMediaServer::GetUrnList(BSTR *pRetval)
{
  char *sz=global_heart.m_pDataBase->GetUrnList(); // works fine, sz is ok
  if (sz)
  {
    *pRetval=_bstr_t(sz);
    delete [] sz;
  }
return S_OK;
}

to obtain a string from an interface, and this:

BSTR x;

((IMediaServer *)ptr)->GetUrnList(&x); // ptr is ok
_bstr_t xx(x, FALSE);
CString szMan;
szMan.Format("%s", xx);
AfxMessageBox(szMan);

to test the stuff. The string in the message box is something unreadable, so i'm asking: where is the mistake?

rechi

Nope (Was: Re: Retreiving BSTR)

19-Jun-02 5:19

Bogdan Rechi wrote:
szMan.Format("%s", xx);

The mistake is there

Format takes variable number of args and so xx would not be converted to char*.

The correct way is

CString szMan;
const char* chxx = xx;
szMan.Format("%s", chxx);

James R. Twine19-Jun-02 8:25

Re: Nope (Was: Re: Retreiving BSTR)

19-Jun-02 8:25

Anonymous wrote:

<br />
CString szMan; <br />
const char* chxx = xx;<br />
szMan.Format("%s", chxx);<br />

That code is attempting to cast a BSTR/_bstr_t to a const char *, which is a no-no.

And, if all you need to so is display the contents of the BSTR as an ASCIIZ string, you can change %s to a %S (uppercase) and it will treat the parameter as a wide string, which is what a BSTR contains:

<br />
// (Typo: "xx" is supposed to be "x", the original BSTR)<br />
// szMan.Format( _T( "%S" ), xx );    // Assuming An ANSI Build Here...  <br />
szMan.Format( _T( "%S" ), x );    // Assuming An ANSI Build Here...  <br />

Peace!

-=- James.
"Some People Know How To Drive, Others Just Know How To Operate A Car."
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Philippe Mori19-Jun-02 9:29

Philippe Mori

19-Jun-02 9:29

This solution suffer from the same problem than the original code that you try to correct...

Conversions operators are not called for function which variables arguments and the whole object is push on the stack.

_bstr_t is not a BSTR. It's an object that contains a pointer to a sub-object that will hold the BSTR and the converted string (if it was asked).

Philippe Mori

Re: Nope (Was: Re: Retreiving BSTR)

James R. Twine19-Jun-02 9:47

19-Jun-02 9:47

> This solution suffer from the same problem than the original
> code that you try to correct...

   If you are referring to my typo, then yes.  If you are saying that I cannot use a BSTR like that, then no.

> Conversions operators are not called for function which variables
> arguments and the whole object is push on the stack

   That is why the format specifiers tell _stprintf/CString::Format(...) how to treat the parameter:

>> szMan.Format( _T( "%S" ), x );

   Under an ANSI build, the "%S" (remember: UPPERCASE) tells CString::Format(...) to treat the passed parameter as a WIDE STRING, which is what x (a BSTR) really is: A BSTR is a specially allocated _wchar_t string with a length value (a DWORD) 4-bytes before the pointer value.

   Peace!

-=- James.
"Some People Know How To Drive, Others Just Know How To Operate A Car."
[Get Check Favorites 1.4 Now!]

James R. Twine19-Jun-02 8:14

19-Jun-02 8:14

Hmmm... I am under the impression that when the temporary bstr_t object is destroyed, it deallocates the BSTR it wrapped...? That would cause the BSTR you return to be invalid. Try looking at the contents (not value) of *pRetval in the debugger right when you get to the delete [] sz line.

You should just be using SysAllocString(...) directly, similar to:

<br />
#include <AFXPriv.h> // -or- <ATLConv.h><br />
<br />
USES_CONVERSION;<br />
<br />
*pRetval = ::SysAllocString( A2CW( sz ) );<br />

Peace!

-=- James.
"Some People Know How To Drive, Others Just Know How To Operate A Car."
[Get Check Favorites 1.4 Now!]

Hans Ruck19-Jun-02 8:31

Hans Ruck

19-Jun-02 8:31

No! The BSTR object is valid. _bstr_t in this case is just attaching itself to the object without handling the memory allocation/deallocation process.
Thanx to both of you for the efforts and time spent.

rechi

James R. Twine19-Jun-02 9:27

19-Jun-02 9:27

   Be VERY CAREFUL here (look into what I say before answering): (Assuming VC++ 6.0 here) When your code assigns the _bstr_t object to the dreferenced BSTR pointer, all you are doing is calling _bstr_t::operator wchar_t*(...), NOT a BSTR-specific operator, which would correctly COPY the BSTR.  When the temporary object goes out of scope, the contained BSTR gets SysFreeString(...)-ed, so you have just returned an already-freed BSTR to the caller!  Sooner or later, code like that is gonna break down.

   Again: do not use a shotgun to kill a fly: correctly use SysAllocString(...) directly to allocate the BSTR that is going to be returned to the caller.

   Peace!

-=- James.
"Some People Know How To Drive, Others Just Know How To Operate A Car."
[Get Check Favorites 1.4 Now!]

Does Anybody Know????

19-Jun-02 4:35

I have a COM object that starts Microsoft Word and opens a word document. The user can make any modifications to the docunment. I added a special button that is going to be used to save the document and exit Microsoft Word. Unfortunately, I am not sure how to capture the event to know the button has been hit. I have looked through the posts and articles and there is a lot of information if you are an ATL server. But this is an MFC-based COM object and is not an ATL server. Does anyone know what do I need to do, in plain english, to determine when my button has been hit. Am I going to have to make it an ATL server to get the event and if so, how do I do that?

PLEASE HELP!!!!!

Confused | :confused:

C^hris L^osinger19-Jun-02 5:57

C^hris L^osinger

19-Jun-02 5:57

you've asked this question at least three times in the past 24 hours. if you haven't received an answer, it's probably because nobody here knows.

-c

Cheap oil. It's worth it!

Image Processing - just like mom used to make.

19-Jun-02 6:56

Way to go dude, I must admit you have to be the biggest jackass I have noticed on this messageboard. If you don't have a reply that is helpful, don't leave any reply at all!

C^hris L^osinger19-Jun-02 7:21

C^hris L^osinger

19-Jun-02 7:21

you didn't really give us much to work with so, what do you expect?

but:

did you try Q183599 in the MSDN "HOWTO: Catch Microsoft Word97 Application Events Using VC++" ?

did you look at: "Automation And Eventing With Microsoft Word" http://www.codeguru.com/atl/wordauto.shtml ?

did you look at: http://www.codeproject.com/com/word_ole_bm.asp ?

how about : http://msdn.microsoft.com/library/en-us/dnguion/html/drgui102599.asp ?

Cheap oil. It's worth it!

Image Processing - just like mom used to make.

19-Jun-02 9:04

Yes, I have looked at all of these examples and they do not necessarily match the scenario I have now. I am using Automation to call MS Word, next I open a document, then I dynamically add a button to the Word toolbar using the commandbars functions. But none of the above examples will work, since they all use ATL and my application does not. All I am looking for is some knowledge as to how I can capture the event that the button that I dynamically created, not one that is on a dialog box or so forth, was pushed. If it was going to cause this much controversy, I would not have put my post out here. I noticed another person's post, Al_ something or other, having a similar problems. So it isn't just me having problems...

By the way, thank you for the advice but it didn't help...

Alan Chambers19-Jun-02 10:01

Alan Chambers

19-Jun-02 10:01

I'm not sure about this, but I may have an idea that may flukily do what you need (though I'm not sure how efficient or how well it conforms to com standards - it is just an idea). Could you not use a hook procedure to grab 'control' of the apps messages and test to see when your button has been pressed by the message that is sent to the app? Not sure about whether this is even capable, just an idea I thought I might share.

Alan.

"When I left you I was but the learner, now I am the master" - Darth Vader

Coding Dilemma

Nic Oughton19-Jun-02 4:34

Nic Oughton

19-Jun-02 4:34

I need to create a wizard to gather information from the userregarding a file.

Currently, I want to use the wizard in two different ways (this may increase in the future)
1. As a standalone wizard
2. As part of a File Open/Save dialog

My dilemma is how to create the wizard.

Should I :
a. Create as a class which is then included in each project where the wizard is required
b. Create as an ATL control which can then be used in any container in the future - even though the wizard is not a simple control e.g. it needs to contain a combo box, edit controls etc. and talk to a database.
c. Create in some other way.

Anyone suggestions are welcome...

Thanks

Nic Wink | ;)

Joaquín M López Muñoz19-Jun-02 5:26

Joaquín M López Muñoz

19-Jun-02 5:26

I'd go for a, which is way simpler than other options. This is how most controls, wizards and other stuff are provided here at CP.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

perlmunger19-Jun-02 9:26

perlmunger

19-Jun-02 9:26

In general it's probably a matter of preference. I would personally create a Static library with the Visual Studio Wizard and put your wizard/DB code in there. Then I would just include that library in whatever project I was using. The reason I choose this method is because I like to statically link things that I have control over. That is just my personal preference, though.

If you have questions about doing what I've suggested, let me know and I'll walk you through it. BTW, did you know that property sheets have a wizard mode? Would accomplish what you are wanting to do pretty easily. Something you may want to look into.

-Matt

------------------------------------------

The 3 great virtues of a programmer:
Laziness, Impatience, and Hubris.
--Larry Wall

Michael P Butler19-Jun-02 9:26

Michael P Butler

19-Jun-02 9:26

Whilst b is a nice option, it means a lot of extra work without much extra gain (unless a third party app is going to call your wizard).

I'd stick with a, you can always wrap it in a COM object later should the need arise.

Michael Smile | :)

Logic, my dear Zoe, merely enables one to be wrong with authority. - The Doctor