Working with registry

[harkoslav]

Thanks again, now i tried to put your code into my and everything seems to be fine expect few little errors which i can't make right =(.

Here is my whole code:

#include "stdafx.h"
#include <Windows.h>
#include <iostream>
#pragma comment(lib, "Advapi32.lib.")

using namespace std;


int main ()
{
	BOOL bGetBinary = FALSE;
	HKEY hKey = NULL;
	if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, TEXT("SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion"), NULL, KEY_QUERY_VALUE, &hKey) == ERROR_SUCCESS)
	{
		DWORD dwType = 0, dwBufferSize = 0;
		if (!bGetBinary)
		{
			dwBufferSize = 260;
			TCHAR tData[260];
			if (RegQueryValueEx(hKey, TEXT("ProductName"), NULL, &dwType, (LPBYTE)&tData, &dwBufferSize) == ERROR_SUCCESS)
			{
				MessageBox(tData);
			}
			else
				MessageBox(TEXT("Error!"));
		}
		else
		{
			dwBufferSize = 1024;
			BYTE bBuffer[1024];
			if (RegQueryValueEx(hKey, TEXT("ProductName"), NULL, &dwType, (LPBYTE)&bBuffer, &dwBufferSize) == ERROR_SUCCESS)
			{
				
			}
			else
				MessageBox(TEXT("Error!"));

		}

	}

I got errors here:

MessageBox(tData);

1 IntelliSense: argument of type "TCHAR *" is incompatible with parameter of type "HWND"

MessageBox(TEXT("Error!"));

3 IntelliSense: argument of type "const wchar_t *" is incompatible with parameter of type "HWND"

MessageBox(TEXT("Error!"));

5 IntelliSense: argument of type "const wchar_t *" is incompatible with parameter of type "HWND"


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

I got following error for all of this lines:
2 IntelliSense: too few arguments in function call



Also 1 more question, after program opens registry value how can I make the program write it's value on the screen? I tried cin << ProductName; but it won't work.

PS. program worked after i erased those messagebox, as it was erased so were the errors.

dwBufferSize = 1024;
			BYTE bBuffer[1024];
			if (RegQueryValueEx(hKey, TEXT("ProductName"), NULL, &dwType, (LPBYTE)&bBuffer, &dwBufferSize) == ERROR_SUCCESS)
			{
				cout << ProductName;
			}

I'm really sorry for being such a pain in the *** but I really don't understand what went wrong now. =(

Any conclusion?


Thanks

[Dadidum]

Messagebox needs a windows handle

AfxMessagebox needs none

[bioHzrdmX]

Sorry, i forgot the HWND parameter, i wrote that code on an MFC app so it just needed the string parameter (as Dadidum said).

To get the code working just change:

MessageBox(tData);
MessageBox(TEXT("Error!"));

to

MessageBox(NULL, tData);
MessageBox(NULL, TEXT("Error!"));

The NULL instead of a window handle (HWND-type parameter, a long-type value) is because MessageBox requires an owner window, and since you don't have any, you can pass a NULL value. Modify the other MessageBox'es and you're done.

If you want to display the value on the screen by using std::cout then you should use the buffer where the values are stored, in this case, the tData variable of the first RegQueryValue:

dwBufferSize = 260;
TCHAR tData[260];
if (RegQueryValueEx(hKey, TEXT("ProductName"), NULL, &dwType, (LPBYTE)&tData, &dwBufferSize) == ERROR_SUCCESS)
{
	wcout << tData;
}
else
	wcout << TEXT("Error!");

The second RegQueryValue gets the raw binary data from the registry in a BYTE array (BYTE equals to unsigned char for windows) and i only included that because you said you wanted to get some binary data, but the info we're getting from the registry in this example is a REG_SZ so the first options is a better choice since it gets the string directly. Play with the code, and again, check the msdn docs (you may use your VS help or try at www.msdn.com) because windows uses a lot of strange data types that you should know about, if you have more questions, please let us know.

And another advice: i used wcout instead of cout because your'e using Unicode, the 'w' before some functions means that it is the 'wide-char' version of the function. Check this post for more advice on cout and wcout http://www.codeguru.com/forum/showthread.php?t=500451

And don't worry, this forum was made to allow us to share our knowledge with others, sometimes we need a little help, sometimes we can give a little help :-)

[harkoslav]

Thanks alot mate, you really helped me!!!
I made it work finally. Btw I tried to send you an private message but you got disabled private messaging. =(

Only thing that confuses me is that "unicode". I guess I'm too new to c++ to understand it right now atm, so im going to study more basics


My FINAL questiond is; xD

Is it possible to send that value (tData) to my website?

[bioHzrdmX]

Hi, sorry about the PM thing, i just forgot to turn it on :-)

Unicode may be a bit confussing for some people (it was for me) but once you learn how to interact with it, you'll be ready to work with Unicode and non-Unicode apps.

It is not more than a type-change: instead of char you'll be using WCHAR, you'll need some new functions (strcpy, printf, etc. will not longer work for you) that are included with the VC++ compiler, the documentation is your best friend. I will also suggest you to read a bit on Windows data types, to learn what is an HWND, an LPTSTR, a DWORD, etc. If you're gonna programming for windows, this is a must. Try to play with API, play a sound, show a message box, create a window, and you'll be above the rest of the coders in a couple of months. I'm a third-year university student and none of my classmates know how to create a window! Imagine the great work opportunities they'll miss!

About your final question: yep, it is possible, the easiest way (i think) is using an API call to launch the browser (ShellExecute) with some parameters on the address (you know something like 'http://www.mysite.com/receive.php?data=something' where 'something' is the value of tData 'printed-out' to the string) but this may be a bit tricky and you will need to write the 'receive.php' code to store or show the value on the web page (requirements: php knowledge and php support on your host) so i think you should try to get better programming skills before trying that :-)

So if you want to become a great coder, you must make a little research, but before trying to run tutorial code, you must learn the essentials about windows, its API and improve your C++ skills, because once you've learned API you will want to make the move to MFC.

Keep the hard work!!
Regards.

[gaar321]

Just to give you help RegOpenKeyEx does not work in XP

[VictorN]

Just to give you help RegOpenKeyEx does not work in XP

Are you sure?

[Arjay]

Lots of old timers prefer the use the brute force method of reading and writing the registry. Me, I'm always looking for the easier approach, yet one that still gets the work done in a reliable and robust manner.

So consider using the ATL CRegKey class. All you need to do for this code to work is #include <atlbase.h>. No other libs or dlls are required.

Here's how easy it is...

CString sProductName;
ULONG ulChars = MAX_PATH + 1;

CRegKey rk;
rk.Open( HKEY_LOCAL_MACHINE, _T("SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion"), KEY_READ );
rk.QueryStringValue( _T("ProductName"), sProductName.GetBuffer( MAX_PATH ), &ulChars );

sProductName.ReleaseBuffer( );

In terms of reading the registry, a good general rule is to only read the registry if the data isn't available via an api.

You can retrieve the ProductName from the GetVersionEx api. No need to read the registry at all for this info. In fact, depending on the OS, the ProductName value may not be present.

[harkoslav]

Thanks for making me know that but could you please explain me how can I make this work:

#include <atlbase.h>

I put that in my code and i got error that it could not get opened.

[Arjay]

Thanks for making me know that but could you please explain me how can I make this work:

#include <atlbase.h>

I put that in my code and i got error that it could not get opened.

What version of Visual C++ are you using?

[harkoslav]

Visual Studio C++ 2010

[VictorN]

Visual Studio C++ 2010

What edition?

[harkoslav]

Microsoft Visual Studio C++ 2010 Express
Version 10.0.30319.1 RTMRel

[VictorN]

AFIK C++ 2010 Express doesn't contain ATL/MFC.

[harkoslav]

Is there a way to upgrade it or something?