Registry usage in MFC Doc/ View - opinions / commentary wanted - C / C++ / MFC Discussion Boards

Richard MacCutchan28-Oct-11 23:13

28-Oct-11 23:13

You've pretty much nailed it, but I have done some tidying up and fixed a couple of minor issues in the code as follows:

C++

WCHAR* CA_Registry::_get_SQLServer_InstalledInstances( void )
{
    HKEY keyHandle;
    WCHAR rgValue[1024];
//  WCHAR szInstance[1024]; // not needed
    // no point in using CString for constant strings
    WCHAR* regPath = L"SOFTWARE\\Microsoft\\Microsoft SQL Server\\";
    WCHAR* regReq = L"InstalledInstances";
    DWORD size1 = sizeof(rgValue);
    // Type; removed as no longer used
    // no need to initialise dwType to zero here
    DWORD dwType;
    // no need to initialise regStatus to REG_MULTI_SZ here
    DWORD regStatus;
 
    int ndx;
    WCHAR *szReturnValue = NULL;
/* variables not needed
    size_t szRgVal;
    int maxStr;
    bool doubleZero;
*/ 
    if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regPath, 0, KEY_QUERY_VALUE, &keyHandle) == ERROR_SUCCESS) {
    // no need to initialise dwType to REG_MULTI_SZ here
        regStatus = RegQueryValueEx( keyHandle, regReq, NULL, &dwType, (LPBYTE)rgValue, &size1);
			
        RegCloseKey(keyHandle);	// we're done with the registry so close the key here
        switch ( regStatus ) {
        case ERROR_SUCCESS:								
/*
 * rewrote this part to use standard (Unicode) functions
            ndx = 0;
            doubleZero = false;
            szRgVal = sizeof(rgValue);
 
            for(int i=0; i < szRgVal; i++) {
                if (!rgValue[i] == L'\0') {
                    szInstance[ndx++] = rgValue[i];
                    doubleZero = false;
                }
                else {
                    if (doubleZero == false) {
                        szInstance[ndx++] = L';';
                        doubleZero = true;
                    }
                    else {
                        szInstance[ndx++] = L'\0\0';
                        break;
                    }
                }                    
            }
 */
            // scan the strings, replacing single nulls by semi-colons
            {
                WCHAR* pszString = rgValue;
                while (*pszString)
                {
                    ndx = wcslen(pszString);
                    // add string length so we point at trailing null character
                    pszString += ndx;
                    if (pszString[1] != L'\0')
                    *pszString++ = L';';    // add semi-colon if not the last string
                }
            }
            /* removed this redundant code
            maxStr = wcslen(szInstance);
            szInstance[maxStr-0] = (char)'\0';
            */
            ndx = wcslen(rgValue);	// we need this value below
            // this also needs to be wprintf, as rgValue is Unicode
            wprintf(L" SQL Server Instance: %s %i\n", rgValue, ndx);				
            // following statement is redundant, we already have the printf
            // cout << "key was read successfully\n";

            // copy to new buffer here
            szReturnValue = new wchar_t[ndx + 1]; // +1 for trailing null character
            wcscpy_s(szReturnValue, ndx + 1, rgValue);
            break;
 
        case ERROR_MORE_DATA:
            cout << "Buffer too small\n";
            // your challenge is to fix the code to handle this be allocating a larger buffer
            break;			
 
        default:			
            cout << "Could not read key\n";
        }
    }
    else {
        cout << "Can not open key";
        cin.ignore();
    }
/* moved this functionality to within success case above
    int strSize = sizeof(szInstance);	
    WCHAR *szReturnValue = new wchar_t[strSize];	
        for(int i = 0; i < strSize; i++) {
        szReturnValue[i]=szInstance[i];		    
    }	
    strSize=wcslen(szReturnValue);	
    szReturnValue[strSize-0]=(WCHAR)L'\0';
 */
    return szReturnValue;  // set above
    // this delete statement will never be reached! Also the calling function needs to delete the buffer when finished with it 
//  delete [] szReturnValue;
}

I hope my comments make sense but please let me know if they don't. I have built and tested this code but I do not have the exact content of the registry value so it may need some minor tweaking.

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

Re: I rewrote the my function for WCHAR

jkirkerx29-Oct-11 7:39

jkirkerx

29-Oct-11 7:39

I had to read it a couple of times before it soaked in, those are huge refinements, but I get it, way more optimized, and it teaches me that alot of the stuff was not needed. Let me make the mods, and I will alter the other registry function I have as well. I didn't know I had to wprintf, I thought it was just for printing to the screen in console.

Thanks

Re: I rewrote the my function for WCHAR

jkirkerx29-Oct-11 8:20

jkirkerx

29-Oct-11 8:20

Works like a charm, I had to move the pszString above the switch because the compiler complained. I changed the function by hand, and only copied the ERROR_Success because it was alot to type. So I have to delete somthing in the calling function, not sure what yet.

WCHAR* CA_Registry::_get_SQLServer_InstalledInstances( void )
{
	HKEY keyHandle;
	WCHAR rgValue[1024];
	WCHAR *regPath = L"SOFTWARE\\Microsoft\\Microsoft SQL Server\\";
	WCHAR *regReq = L"InstalledInstances";
	DWORD size1 = sizeof(rgValue);
	DWORD dwType;
	DWORD regStatus;

	int ndx;
	WCHAR* pszString = rgValue;
	WCHAR *szReturnValue = NULL;
	
	if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regPath, 0, KEY_QUERY_VALUE, &keyHandle) == ERROR_SUCCESS) {
		regStatus = RegQueryValueEx( keyHandle, regReq, NULL, &dwType, (LPBYTE)rgValue, &size1);
		RegCloseKey(keyHandle);	

		switch ( regStatus ) {
			case ERROR_SUCCESS:
				// scan the strings, replacing single nulls by semi-colons
				{
					while (*pszString)
					{
						ndx = wcslen(pszString);
						// add string length so we point at trailing null character
						pszString += ndx;
						if (pszString[1] != L'\0')
						*pszString++ = L';';    // add semi-colon if not the last string
					}
				}
            
				ndx = wcslen(rgValue);	// we need this value below
				wprintf(L" SQL Server Instance: %s %i\n", rgValue, ndx);				
            
				// copy to new buffer here
				szReturnValue = new wchar_t[ndx + 1]; // +1 for trailing null character
				wcscpy_s(szReturnValue, ndx + 1, rgValue);            

				break;

			case ERROR_MORE_DATA:
				cout << "Buffer too small\n";
				break;			

			default:			
				cout << "Count not read key\n";
		}
	}
	else {
		cout << "Can not open key";
		cin.ignore();
	}

	return szReturnValue;	
}

This is the calling function just for reference, I wrote it from scratch, no help, lot cleaner than the registry functions I wrote. It's a rough draft, needs more detail, but in the end, after searching by wire, then search the local machine registry, if nothing is found, I will ask if they want to download the X86 or X64 version, and install it using an automated script that I write on the fly. It's starting to shape up now.

BOOL CA_SQLServer_Scan::_scan_Enumerate_Registry( HWND txtProgress, HWND lblServers, HWND pbProgress )
{
	CA_Registry caReg;
	BOOL bResult = FALSE;
	BOOL bInstance = FALSE;
	int instanceLength;
	WCHAR *szComputerName = NULL;
	WCHAR *szInstanceNames = NULL;
	WCHAR *szCurrentVersion = NULL;
	WCHAR szServerInstance[125];

	// Get the SQL Server instance names
	szComputerName = caReg._get_ComputerName();
	szInstanceNames = caReg._get_SQLServer_InstalledInstances();
	instanceLength = wcslen(szInstanceNames);
			
	if (instanceLength > 0) {

		WCHAR *szInstanceName = NULL;
		WCHAR *token1, *nextToken;
		WCHAR seps[] = L";";
		WCHAR vSeps[] = L".";
		token1 = wcstok_s(szInstanceNames, seps, &nextToken);
		do {
			if (token1 == NULL) { 
				break;
			}
			else {
				szInstanceName = token1;
				szCurrentVersion = caReg._get_SQLServer_Version(szInstanceName);
				
				// Parse the version Numbers
				int szVerValue = wcslen(szCurrentVersion);
				if ( szVerValue > 1 ) {
					WCHAR *szVerMajor = NULL, *szVerMinor = NULL, *szVerBuild = NULL;
					WCHAR *vToken1, *vToken2, *vToken3, *vNextToken;
					int iVerMajor=0, iVerMinor=0, iVerBuild=0;
					
					vToken1 = wcstok_s(szCurrentVersion, vSeps, &vNextToken);
					if (!vToken1 == NULL) {
						szVerMajor = vToken1;
						iVerMajor = _wtoi(szVerMajor);
					}
					
					vToken2 = wcstok_s(NULL, vSeps, &vNextToken);
					if (!vToken2 == NULL) {
						szVerMinor = vToken2;
						iVerMinor = _wtoi(szVerMinor);
					}

					vToken3 = wcstok_s(NULL, vSeps, &vNextToken);
					if (!vToken3 == NULL) {
						szVerBuild = vToken3;
						iVerBuild = _wtoi(szVerBuild);
					}

					WCHAR pbMessage[80];
					wcsncpy_s(pbMessage, _countof(pbMessage), L"Registered: ", wcslen(L"Registered: "));
					//wcsncat_s(pbMessage, _countof(pbMessage), L"LOCAL", wcslen(L"LOCAL"));
					wcsncat_s(pbMessage, _countof(pbMessage), L"\\", wcslen(L"\\"));
					wcsncat_s(pbMessage, _countof(pbMessage), szInstanceName, wcslen(szInstanceName));					
					SetWindowText(txtProgress, pbMessage);
					Sleep(500);
					
					// Analyse the Version Numbers
					switch (iVerMajor) 
					{
					case 11:
						bInstance = TRUE;
						break;
					case 10:
						bInstance = TRUE;
						break;
					case 9:
						bInstance = TRUE;
						break;
					default:
						bInstance = FALSE;
						break;
					}

					if (bInstance) {
						int iComputerName = wcslen(szComputerName);
						int iInstanceName = wcslen(szInstanceName);						
						
						// Build the Computer\\Instance
						wcsncpy_s(szServerInstance, _countof(szServerInstance), szComputerName, iComputerName);
						wcsncat_s(szServerInstance, _countof(szServerInstance), L"\\", wcslen(L"\\"));
						wcsncat_s(szServerInstance, _countof(szServerInstance), szInstanceName, iInstanceName);
						
						// Trim the wChar Array
						iInstanceName=wcslen(szServerInstance);	
						szServerInstance[iInstanceName-0]=(WCHAR)L'\0';

						// Get the Collection Count
						int iCollectionCount;
						iCollectionCount = sqlSrvCollection.Count();

						if (iCollectionCount > 0) {
							// Check for Duplicate
							WCHAR *szComparision = NULL;
							
							for (int i=0; i<iCollectionCount; i++) {
								szComparision = sqlSrvCollection[i];
								if (wcscmp(szServerInstance, szComparision) != 0) {
									int iCollection = sqlSrvCollection.Add();
									sqlSrvCollection[iCollection] = szServerInstance;
								}								
							}							
						}
						else {
							// Add the Server Instance
							int iCollection = sqlSrvCollection.Add();
							sqlSrvCollection[iCollection] = szServerInstance;
						}
					}
				}

				// Get the next token to cycle through
				token1 = wcstok_s(NULL, seps, &nextToken);

			}
		} while (TRUE);
	}
	
	return bResult;
}

Re: I rewrote the my function for WCHAR

Richard MacCutchan29-Oct-11 22:21

Richard MacCutchan

29-Oct-11 22:21

jkirkerx wrote:
I had to move the pszString above the switch because the compiler complained.

Must be a different version than mine. In that case you can delete the extra set of curly braces around the while() loop under case ERROR_SUCCESS:. Looking at the other code you posted I think you are well in control now, you have obviously worked hard on this - time for some R&R on the beach. Good luck.

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

Re: I rewrote the my function for WCHAR

jkirkerx30-Oct-11 6:32

jkirkerx

30-Oct-11 6:32

Well Thanks, I rewrote all my project code last night, and fixed everything in all my modules. I'm determined to get this program out there, so I can start getting people to use my other programs.

I still have the socket issue to fix, and the safe array with comm pointer. I will post those today.

I'll take this afternoon off and hit the sand when it warms up a little, it's 60F outside now.

jkirkerx

Re: I rewrote the my function for WCHAR

Richard MacCutchan30-Oct-11 7:16

Richard MacCutchan

30-Oct-11 7:16

jkirkerx wrote:
I'm determined to get this program out there

You must be getting close now.

jkirkerx wrote:
socket issue ... and the safe array

I should think with what you have learned recently these will (should) be that much simpler.

jkirkerx wrote:
it's 60F outside now.

Well the sun has just gone down here and it's about the same. Unseasonably mild for October in the UK.

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

Re: I rewrote the my function for WCHAR - grovel

Richard MacCutchan29-Oct-11 23:19

Richard MacCutchan

29-Oct-11 23:19

I'd appreciate it if you mark my last post as Good (or Bad) answer, depending on your viewpoint.

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

Registry usage in MFC Doc/ View - opinions / commentary wanted

Vaclav_27-Oct-11 5:18

Vaclav_

27-Oct-11 5:18

I am developing a ham radio logging program and using registry ( my first usage of registry) to save configuration values.
The application is based on SDI MFC document / view architecture..
The “document” (in CDocument) is a CString extracted from user's entry in CFormView.
For this document to be valid an additional “configuration” data are required before the user enters any data into simple CEdit box.
The configuration data are stored in registry and than copied ( on each new start of application) to CDocument and displayed in the CFormView and in configuration ( modal) dialogs as required.
At present I am using SDI , however, would like to be able to add another views in future “improvements”.
Since this is my first usage of registry I would like to hear from anybody if this approach is feasible.
Somehow I feel it is a little too complicated.
As always, thanks for reading.
Vaclav

Re: Registry usage in MFC Doc/ View - opinions / commentary wanted

Albert Holguin27-Oct-11 5:35

Albert Holguin

27-Oct-11 5:35

It's not really that hard once you do it a few times, so it's very feasible... but if there are other options, for example, you can have a file store the configuration. This gives you the added advantage to make it easy for the user to "share" his configuration (since they can just copy the file) and if you make it plain text (which is the best option, as opposed to writing file out in binary), then they can also edit it outside of the program.

Advantage of using the registry is that it doesn't matter where the executable is, it will always find the registry keys. So if the user decides to move the executable (on purpose or by accident), then their settings will still work.

fopen crashed when special characters found.

tagopi27-Oct-11 2:12

tagopi

27-Oct-11 2:12

Hello everybody,

i am trying to create a text file and trying to write something. my problem is with the file name.

FILE *fp;
fp = fopen("c:\test_1/2.txt,"wb");

this special character "/" is not accepting and fp is returning null, and it crashes the system if i try to write something in fp.

i need to keep the file name as like this only.
is there anyway to solve this issue?

Thanks in advance.
A. Gopinath.

Re: fopen crashed when special characters found.

Luc Pattyn27-Oct-11 2:53

Luc Pattyn

27-Oct-11 2:53

if that is a file named test_1/2.txt (and not file 2.txt in some test_1 folder) then the filename IS invalid. You'll have to choose a different name for your file. See here[^].

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Re: fopen crashed when special characters found.

C^hris L^osinger27-Oct-11 3:22

C^hris L^osinger

27-Oct-11 3:22

tagopi wrote:
is there anyway to solve this issue?

yeah, don't call fwrite if your fp is NULL.

image processing toolkits | batch image processing

Re: fopen crashed when special characters found.

David Crow27-Oct-11 4:49

David Crow

27-Oct-11 4:49

tagopi wrote:
is there anyway to solve this issue?

Seeing as how that file cannot be created outside of code (e.g., right-click desktop, new text document, type name), I doubt it.

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"Show me a community that obeys the Ten Commandments and I'll show you a less crowded prison system." - Anonymous

Re: fopen crashed when special characters found.

Andrew Brock27-Oct-11 7:43

Andrew Brock

27-Oct-11 7:43

I think everyone here missed the real issue here.

"c:\test_1/2.txt"

There is a \t in the filename, which is converted to a tab character by the compiler. The file path getting passed into fopen is "c: est_1/2.txt"

You need to escape this backslash with another backslash, so your filename becomes "c:\\test_1/2.txt".

as for the forward slash, windows will interpret this as a path slash too, but you don't need to escape it because the compiler wont change it.

So, the path you are accessing is C: > test_1 > 2.txt

Additionally, fopen will not create the folder "test_1" if it does not exist, it will just fail to open it and return NULL.

Re: fopen crashed when special characters found.

jschell27-Oct-11 8:30

jschell

27-Oct-11 8:30

That however wouldn't cause a crash.
Whereas not testing the return value of the method probably does.

Re: fopen crashed when special characters found.

Andrew Brock27-Oct-11 8:36

Andrew Brock

27-Oct-11 8:36

OK, you are correct. The return value should always be checked for success, but if the filename was valid (and this is where the real issue is) the OP probably would have never noticed that, because it wouldn't be returning NULL.

Re: fopen crashed when special characters found.

Pranit Kothari27-Oct-11 19:01

Pranit Kothari

27-Oct-11 19:01

Hi,
You are not able to create file name having special characters like "/,\,*" etc. If you want to confirm, just go on your desktop and try to create file having name "test_1/2", OS will not even allow to type '/' in file name.

Happy Programming.
Regards

Re: fopen crashed when special characters found.

tagopi27-Oct-11 19:40

tagopi

27-Oct-11 19:40

Thanks everybody for your replies.
will give a try to replace "/" with some other.

Thanks again.
A. Gopinath.

How to refresh folder

MKC00227-Oct-11 0:52

MKC002

27-Oct-11 0:52

If any folder is open in window explorer then how to refresh its contents.
Say c:/xyz is open, it contains some files and folders, i want to progratically refresh the children.

Re: How to refresh folder

Chandrasekharan P27-Oct-11 0:59

Chandrasekharan P

27-Oct-11 0:59

Are you working on mfc?? if yes then, i think you can just redraw whatever it is that you want on the screen.

Every new day is another chance to change your life.

Re: How to refresh folder

Richard MacCutchan27-Oct-11 1:17

Richard MacCutchan

27-Oct-11 1:17

How exactly do you mean "programmatically"? With an external program or an explorer addin?

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

Re: How to refresh folder

MKC0021-Nov-11 6:40

MKC002

1-Nov-11 6:40

My program hides a file say from c: drive. If window explorer is open (c drive) i found file still display. If i refresh window explorer manually then file disappear.

Re: How to refresh folder

App_27-Oct-11 5:38

App_

27-Oct-11 5:38

Here you go.

// Call for each explorer window

        HWND hExplorer = FindWindowEx(GetDesktopWindow(), NULL, L"ExploreWClass", NULL);

        while(hExplorer != NULL)
        {
            EnumChildWindows(hExplorer, RefreshFolderSelectionCB, (LPARAM)&packet);

            hExplorer = FindWindowEx(GetDesktopWindow(), hExplorer, L"ExploreWClass", NULL);
        }
...
...
...

BOOL CALLBACK    RefreshFolderSelectionCB(HWND hWnd, LPARAM lParam)
{
    WCHAR sBuffer[MAX_PATH] = {0};

    ::GetClassName(hWnd, sBuffer, MAX_PATH);

    if (wcscmp(L"SysTreeView32", sBuffer) == 0)
    {
        RefreshFolderSelectionPacket* pPacket = (RefreshFolderSelectionPacket*)lParam;

        // Refreshes the tree nodes that match the contained full paths, and all their open descendants
        // Paths are updated by calling UpdateItem (below)
        // Cache is used across explorer instances to ensure no path is updated twice.

        RefreshSelection(pPacket);
    }

    return TRUE;
}


...
...
static void UpdateItem(IShellFolder* pDesktop, const std::wstring& rsFullPath)
{
    PIDLIST_RELATIVE pIDL;

    if (SUCCEEDED(pDesktop->ParseDisplayName(NULL, NULL, (LPWSTR)rsFullPath.c_str(), NULL, &pIDL, NULL)))
    {
        SHChangeNotify(SHCNE_UPDATEITEM, SHCNF_IDLIST|SHCNF_NOTIFYRECURSIVE|SHCNF_FLUSH, pIDL, NULL);

        ILFree(pIDL);
    }
}

Re: How to refresh folder

David Crow27-Oct-11 5:55

David Crow

27-Oct-11 5:55

http://social.msdn.microsoft.com/Forums/en/windowssdk/thread/cc4a702f-1b2f-4d19-bf68-c88967544172[^]

Where do RefreshFolderSelectionPacket and RefreshSelection() come from?

Re: How to refresh folder

App_27-Oct-11 8:57

App_

27-Oct-11 8:57

uh huh, I ripped that code from there Cool | :cool:

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.