building a string from hexadecimal values - C / C++ / MFC Discussion Boards

Re: found source of error" invalid handle" need help debugging it

C^hris L^osinger4-Sep-02 11:48

4-Sep-02 11:48

yuck.

have you considered using one of the many registry wrapper classes available here on CP ? they can get rid of all of that open/close hassle and they can really clean up your code. i'll never use the registry APIs again.

-c

"I am angry that so many of the sons of the powerful and well-placed... managed to wangle slots in Reserve and National Guard units...Of the many tragedies of Vietnam, this raw class discrimination strikes me as the most damaging to the ideal that all Americans are created equal and owe equal allegiance to their country."
--Colin Powell

ImgSource!

Re: found source of error" invalid handle" need help debugging it

Pavel Klocek4-Sep-02 11:59

Pavel Klocek

4-Sep-02 11:59

Why not use this class?

Pavel
Sonork 100.15206

Re: found source of error" invalid handle" need help debugging it

Michael Dunn4-Sep-02 16:41

Michael Dunn

4-Sep-02 16:41

You have now learned why you need error checking. Wink | ;)

You can look at ATL::CRegKey or any of the registry wrappers here for guidance on how to write the error checks.

--Mike--
Just released - RightClick-Encrypt v1.4 - Adds fast & easy file encryption to Explorer
My really out-of-date homepage
Sonork-100.19012 Acid_Helm

COM Containment

Tim Wallace4-Sep-02 11:02

Tim Wallace

4-Sep-02 11:02

I have a work assignment wherein I have to create a COM object to contain another COM object. The inner object was not aggregatable or poolable on Win2K server, so we needed to wrap it. I'm to the point where I need to pass the function calls to the contained object. My problem is that I can't get an interface pointer to the inner objects custom interface. How would I go about this? I tried creating an IID using the value the inner object registered in the registry, but I keep getting compiler errors when I try that.

How can I create a variable of the type of the inner object's custom interface since I don't have any source/headers for this object (I do have the IDL and the DLL, of course, but that's it).

Time is of the essence here! I'm stuck!

Thanks in advance.

Re: COM Containment

Bill Wilson4-Sep-02 11:11

Bill Wilson

4-Sep-02 11:11

import the .dll and use the CreateInstance method.

Say the interface is named X.A

#import X.dll no_namespace
	IAPtr ppA;

	try {

		CoInitialize(NULL);

		ppA.CreateInstance(__uuidof(A));

                ppA->Somemethod();


		ppCrypt->Release();

		CoUninitialize();

Thanks for the help,
Bill

OOPS correction

Bill Wilson5-Sep-02 7:45

Bill Wilson

5-Sep-02 7:45

The line
ppCrypt->Release();

should read

ppA->Release();

Thanks for the help,
Bill

Insantiating COM Objects

AJ1234-Sep-02 10:49

AJ123

4-Sep-02 10:49

I am trying to play around with an object library. Started looking at it in VB for simplicity. When I imported the type library using class wizzard to create wrappers only a few objects were inserted, when there are tons in VB object browser. Another thing I noticed when i tried to use VBs late-binding using 'createobject' i couldn't access these objects either.

Anyone any clues why I am having trouble accessing these objects from a type library, thats fine when used as a reference in VB?

Cheers
Rich

building a string from hexadecimal values

Kuniva4-Sep-02 10:11

Kuniva

4-Sep-02 10:11

Hey all,

i have all these hexadecimal values(at least i think they are hexadecimal hehe) like this:
74 03 00 00 83 5b 83 8e 6d

etc...
now when you see these characters in notepad some are just blanks.
My question is, how can i make a char that contains a string for example with the hexadecimal values i just gave?
And is there an easier way then to add one character at a time because i have to make a string thats about 90 of those so it would be usefull Smile | :)

Thanks!

Kuniva
--------------------------------------------

Re: building a string from hexadecimal values

Andrew Peace4-Sep-02 10:50

Andrew Peace

4-Sep-02 10:50

They certainly look like hexadecimal to me. How are the values stored?

--
Andrew.

Re: building a string from hexadecimal values

Kuniva4-Sep-02 11:11

Kuniva

4-Sep-02 11:11

well they are stored binary in a file, but i dont want to extract it from there because its only a piece of it and the positions change etc... i just want to build the string from code, that has to be possible no?

Thanks

Kuniva
--------------------------------------------

Re: building a string from hexadecimal values

Christian Graus4-Sep-02 11:54

Christian Graus

4-Sep-02 11:54

use an ifstream to read the values and an ostringstream to build a string out of them. I have some articles on fstreams and ostringstream on CP.

Christian

We're just observing the seasonal migration from VB to VC. Most of these birds will be killed by predators or will die of hunger. Only the best will survive - Tomasz Sowinski 29-07-2002 ( on the number of newbie posters in the VC forum )

Cats, and most other animals apart from mad cows can write fully functional vb code. - Simon Walton - 6-Aug-2002

Adding a data source question

hiseldl4-Sep-02 10:00

hiseldl

4-Sep-02 10:00

I've searched the code project site, but I have been unable to find any articles that show how to add a system dsn through code.

Could someone point me to a snippet of C++ that registers a DSN in the ODBC Data Sources?

I appreciate any help you can give me. Smile | :)

David Hisel -- http://www.hisel.com/

Re: Adding a data source question

Bill Wilson4-Sep-02 11:03

Bill Wilson

4-Sep-02 11:03

I don't have any code, but I can tell you how I've done it. Its really pretty easy. You need to add some entries to the system registry.

These entries define a DSN named APDB.

[HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI\APDB]
"Driver"="C:\\WINNT\\System32\\SQLSRV32.dll"
"Server"="odyw2ksql02"
"Database"="Odyssey_APDB"
"LastUser"="obuser"

[HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI\ODBC Data Sources]
"APDB"="SQL Server"

Re: Adding a data source question

hiseldl4-Sep-02 11:18

hiseldl

4-Sep-02 11:18

Thanks!

This is very helpful, I appreciate it. Smile | :)

David Hisel -- http://www.hisel.com/

Re: Adding a data source question

Pavel Klocek4-Sep-02 12:05

Pavel Klocek

4-Sep-02 12:05

Here is some code to do this:

BOOL CreateSource(LPCSTR lpszDriver, LPCSTR lpszAttributes, BOOL bSystem /*= TRUE*/)
{
	//nahradit '$' nulou ('\0') v lpszAttributes 
	char attr[500];
	char driver[250];

	if(lpszAttributes)
	{
		int mlen = strlen(lpszAttributes);
		strcpy(attr,lpszAttributes);
		char* ch = attr;
		for (int i=0; i<mlen; i++,ch++) {if (*ch == '$') *ch = '\0';}
	}
	else
	{
		attr[0] = 0;
	}

	//Pridani druhe nuly za retezec s driverem
	if(lpszDriver)
	{
		int mlen = strlen(lpszDriver);
		strcpy(driver,lpszDriver);
		strcat(driver,"\0");
	}
	else
	{
		driver[0] = 0;
	}

	WORD request;
	if(bSystem) request = ODBC_ADD_SYS_DSN;
	else request = ODBC_ADD_DSN;

	//zavolani ODBC API
	return SQLConfigDataSource(NULL,request,driver,attr);
}

BOOL CreateAccessSource(LPCSTR lpszName, LPCSTR lpszPath, LPCSTR lpszDescription /*= NULL*/, BOOL bSystem /*= TRUE*/)
{
	char* szDesc;
	szDesc=new char[500];

	if(lpszDescription)
		sprintf(szDesc,"DSN=%s$ DESCRIPTION=%s$ DBQ=%s$ FIL=MicrosoftAccess$ DEFAULTDIR=C:\\$$",lpszName,lpszDescription,lpszPath);
	else
		sprintf(szDesc,"DSN=%s$ DBQ=%s$ FIL=MicrosoftAccess$ DEFAULTDIR=C:\\$$",lpszName,lpszPath);
	
	return CreateSource("Microsoft Access Driver (*.mdb)",(LPCSTR)szDesc,bSystem);
}

Pavel
Sonork 100.15206

Re: Adding a data source question

hiseldl5-Sep-02 5:38

hiseldl

5-Sep-02 5:38

This is great! Thank you.

Note: your code was mis-interpreted as HTML inside the first if block, look at the for loop to see what happened.

Could you send this via email to david at hisel dot com?

Thanks again,

David Hisel -- http://www.hisel.com/

Re: Adding a data source question

Pavel Klocek5-Sep-02 5:43

Pavel Klocek

5-Sep-02 5:43

I fixed it.

Pavel
Sonork 100.15206

graceful exit, and safeguards - help!

ns4-Sep-02 9:45

4-Sep-02 9:45

My program depends on the user choosing a database, and then an images folder. Two issues arise:

If they browse to a random database, it will crash of course. If I can somehow take a look inside and see if it has a table called "tblTest" , I can potentially avert the crash. So thats

Q1 - how to peek in a db and see if its table has a particular name.

Q2 - If by chance or perversity the user chooses a random folder with none of the expected images in it, a grand crash ensues. How can I exit gracefully in case this happens? I dont mind terminating the app if need be - ideally they get a second chance to choose the right folder. The folder has a bunch of bmps in it.

Confused | :confused:

I feel like there is no solution, but I have seen apps where such mistakes are forgiven...

thanks,
ns

Re: graceful exit, and safeguards - help!

C^hris L^osinger4-Sep-02 10:00

C^hris L^osinger

4-Sep-02 10:00

ns wrote:
If by chance or perversity the user chooses a random folder with none of the expected images in it, a grand crash ensues. How can I exit gracefully in case this happens?

IMO, the real question you should be asking is "why is there a crash at all?" you should be checking for possible error situations everywhere, and acting accordingly at all times. it's a bad idea to assume every situation is a good one.

if you really need to exit immediately, try PostQuitMessage. but, that's really not much better than simply crashing, since the user has no clue as to what went wrong in either case.

-c

ImgSource!

Re: graceful exit, and safeguards - help!

Stephane Rodriguez.4-Sep-02 10:44

Stephane Rodriguez.

4-Sep-02 10:44

ns wrote:
If they browse to a random database, it will crash of course

You access the database through a db driver, right ? So, depending on the database (sql server, oracle, mysql, ...) you have system tables describing user tables.

And I swallow a small raisin.

Re: graceful exit, and safeguards - help!

Tomasz Sowinski4-Sep-02 23:01

Tomasz Sowinski

4-Sep-02 23:01

Just handle the db errors - depending on the data access technology you're using, you may have to check error code or catch appropriate exception.

Tomasz Sowinski -- http://www.shooltz.com

** Putt knot yore thrust inn spel chequers. **

CRichEditCtrl and URL link …

Hadi Rezaee4-Sep-02 9:06

Hadi Rezaee

4-Sep-02 9:06

Hi there,
Is there way to show URL address in CRichEditCtrl like URL link in webpages ??
I mean when user hit the link in the CRichEditCtrl my program open browser …

Please help me …

My month article: Game programming by DirectX by Lan Mader.
Please visit in: www.geocities.com/hadi_rezaie/index.html

Hadi Rezaie

Re: CRichEditCtrl and URL link …

Matthew R. Miller4-Sep-02 10:22

Matthew R. Miller

4-Sep-02 10:22

Yeah, but the user has to have RichEdit 2.0 on the system, so make sure you program a fail safe... most will have it but all it takes is that one who doesn't. But any way here you go.

<br />
	<br />
	// Initiallize<br />
	HANDLE m_hRichEdit2 = LoadLibrary(_T("RICHED20.DLL"));<br />
	if (m_hRichEdit2 == NULL)	<br />
	{		<br />
		// You could not allow them to run your program at all, or work around people who don't have 2.0<br />
		AfxMessageBox("Failed to initialize rich edit 2.0", MB_OK | MB_ICONEXCLAMATION);		<br />
		return FALSE;	<br />
	} <br />
	<br />
	// Turn it on and off<br />
	CRichEditCtrl m_ctlEdit;<br />
	// -- On<br />
	if (m_hRichEdit2 != NULL)<br />
		m_ctlEdit.SendMessage(EM_AUTOURLDETECT, (WPARAM)TRUE, 0);	<br />
	// -- Off<br />
	if (m_hRichEdit2 != NULL)<br />
		m_ctlEdit.SendMessage(EM_AUTOURLDETECT, (WPARAM)FALSE, 0);<br />
	<br />
	<br />
	// Don't forget to clean up<br />
	if (m_hRichEdit2 != NULL)<br />
	{<br />
		::FreeLibrary(m_hRichEdit2);<br />
	}	<br />
<br />

<><><><><><><><><><><><><><>
Matthew R. Miller
mattrmiller@computersmarts.net
www.computersmarts.net

Re: CRichEditCtrl and URL link …

Hadi Rezaee4-Sep-02 10:34

Hadi Rezaee

4-Sep-02 10:34

Coool, Thanks for sample Big Grin | :-D

I have just a little question about your code ...
So, By your source code, if i have a URL address, RichEdit box make link for it, automaticly ... right ???

My month article: Game programming by DirectX by Lan Mader.
Please visit in: www.geocities.com/hadi_rezaie/index.html

Hadi Rezaie

Re: CRichEditCtrl and URL link …

Matthew R. Miller4-Sep-02 10:45

Matthew R. Miller

4-Sep-02 10:45

Yup! Just like in Outlook or Outlook Express Smile | :)

<><><><><><><><><><><><><><>
Matthew R. Miller
mattrmiller@computersmarts.net
www.computersmarts.net

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