C / C++ / MFC

Re: Calculated values from different functions to a single function.

11-Nov-07 22:19

Seems to me, my explanation is not clear of the question. Please look at the replay for baerten.

I appreciate your help all the time...
Eranga Smile | :)

only coder11-Nov-07 22:29

only coder

11-Nov-07 22:29

typedef struct tagRET_VAL
{
int code;
void* pValue;
}RET_VAL, *PRETVAL;

enum CODE{ CODE_INT, CODE_STRING };

void fun1()
{
int a = 10;

RET_VAL rv;
rv.code = CODE_INT;
rv.pValue = &a;
return &rv;
}

void fun2()
{
char s[] = "hello";

RET_VAL rv;
rv.code = CODE_STRING;
rv.pValue = s;
return &rv;
}

void GetValue( PRET_VAL pRV )
{
switch( pRV->code )
{
case CODE_INT:
// do something with (int *)pRV->pValue ....
break;
case CODE_STRING:
// do something with (char *)pRV->pValue ...
break;
}
}

Re: Calculated values from different functions to a single function.

Xing Chen11-Nov-07 22:35

Xing Chen

11-Nov-07 22:35

I seems you want to use other process's function,as your's.
I suggest you do it in Inject dll,and return result to your application.
hope this article will be help you:
http://www.codeproject.com/library/InjLib.asp[^]

ADO, Can Bookmark be used to remember the current position of record? [modified]

followait11-Nov-07 21:48

followait

11-Nov-07 21:48

I do it like this:

<br />
_variant_t Bookmark=m_pRS->Bookmark;<br />
//use m_pRS->Move() move around<br />
m_pRS->Bookmark=Bookmark //want it back, is it true?<br />

However, in some case an error will occur in the statement:

<br />
_variant_t Bookmark=m_pRS->Bookmark;<br />

I used try-catch, it's an unknown error.

What I want to do is to remeber the current position for back.
Is there an efficient way?
And How to make my recordset support bookmark?

Thanks very much.

-- modified at 4:28 Monday 12th November, 2007

Back to the roots

Rage11-Nov-07 21:26

Rage

11-Nov-07 21:26

I have an visual c++6.0 dll workspace, that I would like to compile as a lib. Is it necessary to create a new dsp, or may I screw the settings of the dll dsp so that it can compile as a static lib ?

And yes, I do feel ashamed to still have to ask such basic questions Blush | :O

Thanks,
RaGE

~RaGE();

I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus

Do not feed the troll ! - Common proverb

baerten11-Nov-07 21:47

baerten

11-Nov-07 21:47

In the procect-explorer, you choose your project and click on properties.
or in the main-menu on project -> <your_projectname> settings

There'in you have the possibility to choose the kind of "output" DLL,LIB or EXE.
Then you choose LIB. You find this page at "configuration-properties"

I hope it works Wink | ;)

BTW: my visual studio is in german, so i don't know the exact names of the menu-elements Smile | :)

Rage11-Nov-07 22:13

Rage

11-Nov-07 22:13

baerten wrote:
There'in you have the possibility to choose the kind of "output" DLL,LIB or EXE.

In which tab is this exactely ( Did you notice Visual C++6.0) ?

baerten wrote:
my visual studio is in german, so i don't know the exact names of the menu-elements

Mine too

~RaGE();

I think words like 'destiny' are a way of trying to find order where none exists. - Christian Graus

Do not feed the troll ! - Common proverb

Nelek11-Nov-07 22:33

Nelek

11-Nov-07 22:33

Projekt -> Einstellungen (ALT+F7) (Benutzer definiertes)

But actually I think you should do nothing. The compilation already gives you the *.dll, *.lib and *.def

You choose what you want to use, when integrating the dll in other projekt. Static or dinamic

BTW, have your tried "Erstellen -> Alles neu erstellen...?"

Greetings.

--------
M.D.V.

If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?

Help me to understand what I'm saying, and I'll explain it better to you

“The First Rule of Program Optimization: Don't do it. The Second Rule of Program Optimization (for experts only!): Don't do it yet.” - Michael A. Jackson

Wink | ;)

baerten11-Nov-07 23:10

baerten

11-Nov-07 23:10

Ah sch***, zu flott gelesen, sorry.

Ist super lange her das ich Visual C++ 6.0 genutzt habe, aber das muss auch in den
Projekt-Einstellungen zu finden sein. Denn das erstellen einer .lib oder .dll ist ein
fundamentales Kriterium das auch schon Version 6.0 ermöglichen sollte.

Leider habe ich kein 6.0 installiert, sonst würde ich mal nachsehen wo sich dieser Menüpunkt verstecken könnte...

Aber Nelek könnte schon die Lösung haben Smile | :)

Viel Glück

platform specific API or C standard API

Nelek11-Nov-07 23:18

Nelek

11-Nov-07 23:18

The menu option you told was right. I think is in the "Linker" tab, there are two fields that say:

Name der Ausgabedatei: Release/MyDll.dll

Objekt-/Bibliothek-Module: (for me is empty)

But as I said, when I compile I have all the files in the debug/release folder. The *.dll, *.lib and the *.exp

So I guess not much work is needed.

In the worst case, create a new dll project. Open the *.cpp, *.h and *.def files. Copy/paste the code into the created project and compile.

George_George11-Nov-07 20:23

George_George

11-Nov-07 20:23

Hello everyone,

Are there any official site to check whether an API (like tolower or toLower) is platform specific API (e.g. Microsoft platform specific, Linux specific) or C common standard API?

thanks in advance,
George

Matthew Faithfull11-Nov-07 22:47

Matthew Faithfull

11-Nov-07 22:47

You need a copy of the ANSI C standard ISO/IEC 9899:1999 to see if a C Library function like tolower is in the standard. ( A draft is on the web but you're supposed to buy it )
You need to check the MSDN documentation for any standard API to see if Microsoft implemented it and glibc at www.gu.org is usually the place to look to see if Linux supports it. Not all in all an easy task. If you want to know more you could email me.

Nothing is exactly what it seems but everything with seems can be unpicked.

George_George11-Nov-07 23:09

George_George

11-Nov-07 23:09

Thanks Matthew,

I have found it.

regards,
George

Rajasekharan Vengalil11-Nov-07 22:53

Rajasekharan Vengalil

11-Nov-07 22:53

When using MSDN you'd typically see a "Requirements" section where compatibility information is given. If an API is part of the ANSI standard then it puts the text "ANSI" in the "Compatibility" column. See here[^].

--
gleat
http://blogorama.nerdworks.in[^]
--

How to check that ADO connection is successfully open or not.

George_George11-Nov-07 23:11

George_George

11-Nov-07 23:11

Thanks gleat,

You are so cool.

regards,
George

CodingLover11-Nov-07 19:25

Re: How to check that ADO connection is successfully open or not.

11-Nov-07 19:25

Hi all,

I've create a ADO connection to connect a SQL database to my application as follows.

<br />
	ADODB::_ConnectionPtr pConn;<br />
	ADODB::_RecordsetPtr pRecSet;<br />
<br />
	GetADOCon( srf_SQL, pConn, pRecSet );<br />
	sqlStr.Format( "SELECT * FROM RecordData" );<br />
	hr = pRecSet->Open( _bstr_t(sqlStr), pConn.GetInterfacePtr(), ADODB::adOpenDynamic, ADODB::adLockOptimistic, -1);<br />

It works fine on my application. But I want to avoid future issues that opening the database/dataset and check it is exist or not.

How can I do that.

Can I use SUCCEED to assert my application.

Thanks.

I appreciate your help all the time...
Eranga Smile | :)

CodingLover11-Nov-07 21:18

Re: How to check that ADO connection is successfully open or not.

11-Nov-07 21:18

I've done it simply as follows.

<br />
		if (FAILED(hr))<br />
		{<br />
			AfxMessageBox( "Open Database connection Failed." );<br />
		}<br />

How far this way is efficient to use.

I appreciate your help all the time...
Eranga Smile | :)

Rajasekharan Vengalil11-Nov-07 22:41

Rajasekharan Vengalil

11-Nov-07 22:41

From the code snippet you posted earlier I gather that you are using #import to import the ADO type declarations. Depending on what attributes you used while writing your #import statement the HRESULTs returned by COM methods might be swallowed by the wrapper class that the compiler generates for you (in the ".tli" file) and get translated into C++ exceptions throwing _com_error objects. So you might want to handle that exception.

--
gleat
http://blogorama.nerdworks.in[^]
--

Re: How to check that ADO connection is successfully open or not.

CodingLover11-Nov-07 22:47

11-Nov-07 22:47

Of course, yes. I've already wrote few classes to handle that exception. Smile | :)

Actually that my question is part of a error handling class. Big Grin | :-D

I appreciate your help all the time...
Eranga Smile | :)

Using Semaphore

narayanagvs11-Nov-07 19:09

narayanagvs

11-Nov-07 19:09

Hi,

I have a Pdf file which I want to run from my Application.

I want to restrict copy access to a file when I open the file using the my application.

Can I restrict access to that Pdf file by placing a lock on that file? So that only my application accesses it and no one can access the file.Is that a possible Solution?

Any Suggestions would be helpful.

Thanks

Today is a gift, that's why it is called the present.

Naveen11-Nov-07 19:45

Naveen

11-Nov-07 19:45

narayanagvs wrote:
when I open the file using the my application.

Through which API ur opening the file? Another applications, such as explorer cannot copy a file if it is already opened with the share deny ready permission.

Check the "DWORD dwShareMode" parameter in the CreateFile() API.

nave

[OpenedFileFinder]

Cedric Moonen11-Nov-07 20:18

Cedric Moonen

11-Nov-07 20:18

narayanagvs wrote:
Can I restrict access to that Pdf file by placing a lock on that file? So that only my application accesses it and no one can access the file.Is that a possible Solution?

You mean using a semaphore ? If that's the case, then the answer is no. A semaphore has to be used by all parties that want to access a resource (whatever it might be). So, in all the programs that wants to access the resource, they need to use the same semaphore.
If you lock your file in your application through a semaphore, nothing prevent explorer (for example) to open the file (because it doesn't use a semaphore to open the file).

Cédric Moonen
Software developer

Charting control [v1.2]

narayanagvs12-Nov-07 0:55

narayanagvs

12-Nov-07 0:55

Cedric Moonen wrote:
You mean using a semaphore ? If that's the case, then the answer is no

If not semaphores, Is there any way to do that?

Thanks

Today is a gift, that's why it is called the present.