C / C++ / MFC Discussion Boards

David Crow1-Apr-04 7:55

1-Apr-04 7:55

It's actually in place to squelch another compiler warning: C4101. A variable was declared, but never used. You can add a #pragma warning(disable:4507) statement if you don't like the C4065 warning.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: What is UNUSED used for?

Jesse Evans1-Apr-04 8:25

Jesse Evans

1-Apr-04 8:25

Thanks, David!

I think you meant disable:4065, but that was enough to overcome my issue.

BTW, why is this sprinkled all over Microsoft's code? Shouldn't one simply remove the reference to the unused variable?

Long Live CodeProject!

'til next we type...
HAVE FUN!! -- Jesse

Re: What is UNUSED used for?

grigsoft1-Apr-04 8:36

grigsoft

1-Apr-04 8:36

> Shouldn't one simply remove the
> reference to the unused variable?

It depends. Consider this:

void myfunc1(LPVOID p)<br />
{<br />
  ASSERT(p);<br />
  // do smth without p<br />
  // may be later we will use it<br />
}<br />

It's a bit non-natural, but it give you an idea - item can be used in one configuration, but unused in another.
Or maybe this one is better:

void myfunc2(LPVOID p)<br />
{<br />
#ifdef _UNICODE<br />
  // do smth with p<br />
#else<br />
 UNUSED_ALWAYS(p);<br />
 // do smth without p<br />
#endif<br />
}

Igor Green
http://www.grigsoft.com/ - files and folders comparison tools

Re: What is UNUSED used for?

David Crow1-Apr-04 8:39

David Crow

1-Apr-04 8:39

Jesse Evans wrote:
I think you meant disable:4065, but that was enough to overcome my issue.

You're right. Blush | :O

How I got C4507 is anyone's guess.

Jesse Evans wrote:
BTW, why is this sprinkled all over Microsoft's code? Shouldn't one simply remove the reference to the unused variable?

I'm not sure. Have a look at the USES_CONVERSION preprocessor directive. It will declare a variable and then use that variable all by itself in a statement just to keep the compiler from complaining about an unreferenced variable.

There's also the case of unreferenced function parameters. With C++, you can declare a function and omit the names of any unused parameters. With C that was not possible, so inside of the function, you could use the UNUSED() macro to get ride of the C4101 warning. Make sense?

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: What is UNUSED used for?

Jesse Evans1-Apr-04 8:51

Jesse Evans

1-Apr-04 8:51

Thanks, Igor and David. Makes sense, now.

'til next we type...
HAVE FUN!! -- Jesse

Monitoring a network directory

LKogut1-Apr-04 7:32

LKogut

1-Apr-04 7:32

Hi all,

I need to monitor the NT/2000/XP network environment for files that I have created and files that I have renamed.
I based my program on the FWATCH example of MSDN, i.e., I'm using ReadDirectoryChangesW and IO Completion Port to receive the notification.
The problem is that I also get notified when some other user (not me) creates or renames a file on the directory that I am monitoring.
Is there any way to filter the notifications so that I only get notified when I create or rename files? If not, is there any way to know which user caused the notification?
Thanks.

Re: Monitoring a network directory

David Crow1-Apr-04 8:50

David Crow

1-Apr-04 8:50

LKogut wrote:
Is there any way to filter the notifications so that I only get notified when I create or rename files? If not, is there any way to know which user caused the notification?

When a file is created, you can use GetNamedSecurityInfo() and LookupAccountSid() to see if the current owner of the file is you. Also, if renaming a file causes the owner to change, this will work too.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Monitoring a network directory

LKogut2-Apr-04 1:35

LKogut

2-Apr-04 1:35

Thanks David, this will help me for sure!
But, unfortunately, not 100%. Looking for the functions on the help, they only work on an NTFS file system. Any clue for non NTFS file system?

Resizing PropertyPages

act_x1-Apr-04 7:25

act_x

1-Apr-04 7:25

How do I resize my PropertySheet and all pages based on size of the Main Dialog ?

I derived a class from PropertySheet and tried to implement an OnInitDialog .
Here's what i tried but didnt come out good

BOOL CMainSheet::OnInitDialog() {<br />
 CPropertySheet::OnInitDialog();<br />
 CWnd *parentWnd = this->GetOwner();<br />
 ASSERT(parentWnd);<br />
  parentWnd->GetClientRect(&parentRect);<br />
 CTabCtrl *pTab = GetTabControl();<br />
 ASSERT(pTab);<br />
 this->SetWindowPos(0,parentRect.left,parentRect.top,200,200,0);<br />
 pTab->SetWindowPos(0,parentRect.left,parentRect.top,200,30,0);<br />
<br />
<br />
 CPropertyPage *page = GetActivePage();<br />
 ASSERT(page);<br />
 this->GetClientRect(&r);<br />
 page->SetWindowPos(0,r.left,r.top,180,180,0)<br />
 return TRUE ;<br />
}

Please advise

CArray on the heap

sschilachi1-Apr-04 6:17

sschilachi

1-Apr-04 6:17

Is there any way to create a CArray object on the heap rather than on the stack?

Thanks

Re: CArray on the heap

David Crow1-Apr-04 6:49

David Crow

1-Apr-04 6:49

Yes, but why would you want to? As you add items to the array, memory is allocated from the heap to hold the individual items. The array object itself consumes very little memory.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: CArray on the heap

Ravi Bhavnani1-Apr-04 7:08

Ravi Bhavnani

1-Apr-04 7:08

My guess is he wants it to exist outside the scope of the creating block.

/ravi

My new year's resolution: 2048 x 1536
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ravib@ravib.com

Re: CArray on the heap

Navin1-Apr-04 7:38

Navin

1-Apr-04 7:38

Simple:

CArray<int> *theArray = new CArray<int>;
// Examples of populating the array
theArray->Add(1);
theArray->Add(42);
theArray->SetAt(0, 1337);

Or am I missing something? Confused | :confused:

Remember, even if you win the rat race, you're still a rat.

Problem with strings conversion

doctorpi1-Apr-04 6:05

doctorpi

1-Apr-04 6:05

Hi guys
I've got this

CString file;
HANDLE hFile = CreateFile( ?????,........

What I have to put in ????? to get a valid value in hfile,all my tries have finished with a -1.
LPCSTR(file) doesn't work and I don't know what to do.
Thanks
Doc

Re: Problem with strings conversion

Ravi Bhavnani1-Apr-04 6:33

Ravi Bhavnani

1-Apr-04 6:33

See this[^] link.

/ravi

My new year's resolution: 2048 x 1536
Home | Articles | Freeware | Music
ravib@ravib.com

Re: Problem with strings conversion

doctorpi1-Apr-04 6:42

doctorpi

1-Apr-04 6:42

Already read,but sorry, I can't see the solution.
My question is, how can I convert a CString to the right parameter to the CreateFile method?
Thanks
Doc

Re: Problem with strings conversion

Ravi Bhavnani1-Apr-04 6:49

Ravi Bhavnani

1-Apr-04 6:49

CString strFile = _T("C:\\myfile.txt");
HANDLE hFile = CreateFile (strFile, GENERIC_WRITE, 0, NULL, CREATE_NEW, 0, NULL);

/ravi

My new year's resolution: 2048 x 1536
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ravib@ravib.com

Re: Problem with strings conversion

doctorpi1-Apr-04 6:58

doctorpi

1-Apr-04 6:58

Sorry, it has been my fault.
My problem comes maybe from the point that I can't assign my file directly putting double \\.
// My Code
TCHAR m_szDrive[10];
TCHAR m_szDir[MAX_PATH];
TCHAR m_szFullPath[MAX_PATH];
CString sFile;
// Application Path
::GetModuleFileName(NULL,m_szFullPath,MAX_PATH);
_splitpath(m_szFullPath,m_szDrive,m_szDir,NULL,NULL);
sFile=m_szDrive;
sFile+=m_szDir;
sFile+=_T("myfile.txt");
CreateFile(sFile,.... THAT DOESN'T WORK
Do you know how can I convert my string to the right parameter?
Thanks for your patience.
Doc

Re: Problem with strings conversion

Ravi Bhavnani1-Apr-04 7:06

Ravi Bhavnani

1-Apr-04 7:06

TCHAR*  pSlash = NULL;            // location of last backslash filespec
TCHAR   szFilespec [_MAX_PATH];   // filespec

// Get filename of .exe file sans name
::GetModuleFileName (AfxGetInstanceHandle(), szFilespec, _MAX_PATH);
pSlash = _tcsrchr (szFilespec, _T('\\'));
ASSERT (pSlash != NULL);
pSlash++;
*pSlash = _T('\0');
CString strFilename = szFilespec + _T("myFile.txt");
hFile = Create (strFilename, ...)

/ravi

My new year's resolution: 2048 x 1536
Home | Articles | Freeware | Music
ravib@ravib.com

Re: Problem with strings conversion

doctorpi1-Apr-04 7:14

doctorpi

1-Apr-04 7:14

I've corrected
error C2110: cannot add two pointers
CString strFilename = szFilespec + _T("myFile.txt");
but still same problem sorry Frown | :(

Doc

Re: Problem with strings conversion

Ravi Bhavnani1-Apr-04 7:20

Ravi Bhavnani

1-Apr-04 7:20

CString strFilename = szFilespec;
strFilename += _T("myFile.txt");

/ravi

My new year's resolution: 2048 x 1536
Home | Articles | Freeware | Music
ravib@ravib.com

Re: Problem with strings conversion

doctorpi1-Apr-04 7:24

doctorpi

1-Apr-04 7:24

As I said in my last post, I've already corrected this compiler error and still the same problem.
Sorry Frown | :(

Doc

Re: Problem with strings conversion

Paul Ranson2-Apr-04 0:19

Paul Ranson

2-Apr-04 0:19

This works,

<br />
        TCHAR m_szDrive[10];<br />
        TCHAR m_szDir[MAX_PATH];<br />
        TCHAR m_szFullPath[MAX_PATH];<br />
        CString sFile; <br />
        // Application Path <br />
        ::GetModuleFileName(NULL,m_szFullPath,MAX_PATH);<br />
        _splitpath(m_szFullPath,m_szDrive,m_szDir,NULL,NULL); <br />
        sFile=m_szDrive;<br />
        sFile+=m_szDir;<br />
        sFile+=_T("myfile.txt");<br />
    //    CreateFile(sFile,.... THAT DOESN'T WORK<br />
        HANDLE h = ::CreateFile ( sFile,<br />
                                GENERIC_WRITE,<br />
							    FILE_SHARE_READ,<br />
							    NULL,<br />
							    OPEN_ALWAYS,<br />
							    FILE_ATTRIBUTE_NORMAL,<br />
							    NULL ) ;<br />

Given that your code appears to compile the problem is probably down to the arguments to 'CreateFile'. What are you using?

Paul

Visual C++.NET version 2003

DennisTheMenace1-Apr-04 5:56

DennisTheMenace

1-Apr-04 5:56

Anybody out there have this very frustrating problem?:
When I build my project, Visual often hangs and I have to kill the Visual C++.NET process and start over. It happens on a regular basis and the "Stop build" button does not work. It is very frustrating!!!

GetMenuItemInfo access violation in user32.dll

jphillips_2003@hotmail.com1-Apr-04 5:48

jphillips_2003@hotmail.com

1-Apr-04 5:48

when accessing from another process.
All variables have not null values.

void getMenuItem(HWND hWndMenu)
{
HMENU menu = GetMenu(hWndMenu);
MENUITEMINFO mi, *_mi; unsigned long pid;
HANDLE process;

GetWindowThreadProcessId(hWndMenu, &pid);
process=OpenProcess (PROCESS_VM_OPERATION|PROCESS_VM_READ|PROCESS_VM_WRITE|PROCESS_QUERY_INFORMATION, FALSE, pid);
_mi=(MENUITEMINFO*)VirtualAllocEx(process, NULL, sizeof(MENUITEMINFO), MEM_COMMIT, PAGE_READWRITE);

ZeroMemory(&mi, sizeof(MENUITEMINFO));

mi.cbSize = sizeof(MENUITEMINFO);
mi.fMask = MIIM_TYPE;
mi.fType = MFT_STRING;
mi.dwTypeData=NULL;
WriteProcessMemory(process, _mi, &mi, sizeof(MENUITEMINFO), NULL);
// this fails GetMenuItemInfo(menu, 1, true, _mi);
ReadProcessMemory(process, _mi, mi, sizeof(MENUITEMINFO), NULL);
int size = mi.cch;
VirtualFreeEx(process, _mi, 0, MEM_RELEASE);

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