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According to MSDN:
Because the new block can be in a new memory location, the pointer returned by realloc is not guaranteed to be the pointer passed through the memblock argument.
Does this mean I have to manually delete the previous pointer or will this stomp on the memory just allocated...?
I'm thinking freeing the previous pointer would cause serious problems...but i'm unsure...
Could you fill me in please...?
Thanx! 
"An expert is someone who has made all the mistakes in his or her field" - Niels Bohr
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You have truncated the text where it says the buffer is potentially reallocated, which means a balance free.
Now you have the CRT code, in realloc.c, it executes this :
if ( (retp = _malloc_base(newsize)) != NULL ) {
memcpy(retp, pblock, oldsize);
_free_base_lk(pblock);
}
Which is the answer to your question.
There is also another way of seeing whether the previously allocated block has been freed or not : the dummy characters. In DEBUG mode, your block will be filled with either of these :
<br />
char _bNoMansLandFill = 0xFD; <br />
char _bDeadLandFill = 0xDD; <br />
char _bCleanLandFill = 0xCD; <br />
In your case, that's DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD.
How low can you go ?
(MS rant)
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So in laymen terms, thats a NO...i don't have to free the previous pointer...? 
Cheers!
"An expert is someone who has made all the mistakes in his or her field" - Niels Bohr
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Exactly.
I wanted to have a neat post about that, so to reference it whenever someone ask the same question. That said, I am pretty sure next time I'll have to rewrite the whole sh*t again.
How low can you go ?
(MS rant)
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I use Spy++ "window Search" dialog. I drag and drop mouse pointer over target window. In result Spy++ shown me the handle of window, caption and class name.
Suppose I got class name like "sysListView32". Now i want to know that which system dll is exporting this class. How can i find that ??
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Well Spy++ won't help you there. I think your best shot is to check MSDN - I think in this case it's commctrl32.dll (not sure about the spelling though )
Wenn ist das Nunstück git und Slotermeyer? Ja! Beierhund das oder die Flipperwaldt gersput!
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Class shown in Spy++ is result of RegisterClassEx call made when window is created. This is not class exported from Dll.
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Hi, This is a problem about DLL and EXE. The DLL was past debugging and made a *.dll and *.lib. Everything is wrong in Exe.
In DLL:
First, I made a class named CDecoder.
Inside it I declare member m_FormatTable
CFormatTable m_FormatTable;
I followed wizard to make a class CFormatTable which wrapped a table named "Format" in my database.
CDecoder's member function Initialize() use CFormatTable to load necessary data from the database.
In Exe,
I wrote:
CDecoder Decoder;
Decoder.Initialize();
and got the following:
------------------Configuration: HydroExe - Win32 Debug--------------------
Linking...
Creating library Debug/HydroExe.lib and object Debug/HydroExe.exp
Decoder.obj : error LNK2001: unresolved external symbol "public: __thiscall CFormatTable::CFormatTable(class CDatabase *)" (??0CFormatTable@@QAE@PAVCDatabase@@@Z)
Debug/HydroExe.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.
HydroExe.exe - 2 error(s), 0 warning(s) What's wrong?
Extreme programming. Do the No.1
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Did you export the class CFormatTable from the DLL ?
Check out
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Link did not show up
http://www.codeproject.com/dll/dllexport.asp
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I am getting a wierd error and I think it is because something may be declared wrong, I guess I am just not sure where:  Any clues?
Inside header file:
friend ostream &operator << (ostream &, ListNode &);
Inside .cpp file:
ostream &operator << (ostream &strm, ListNode& *Node)
{
while(Node != NULL)
{
...
}
return strm;
}
Errors:
<br />
--------------------Configuration: records - Win32 Debug--------------------<br />
Compiling...<br />
records.cpp<br />
C:\Documents and Settings\User\Desktop\cs208\hw6\records.cpp(101) : error C2061: syntax error : identifier 'ListNode'<br />
C:\Documents and Settings\User\Desktop\cs208\hw6\records.cpp(102) : error C2805: binary 'operator <<' has too few parameters<br />
C:\Documents and Settings\User\Desktop\cs208\hw6\records.cpp(104) : error C2065: 'Node' : undeclared identifier<br />
Error executing cl.exe.<br />
<br />
records.obj - 3 error(s), 0 warning(s)<br />
Nick Parker
May your glass be ever full.
May the roof over your head be always strong.
And may you be in heaven half an hour before the devil knows you’re dead. - Irish Blessing
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 It seems like the compiler doesn't recognize the ListNode type. Make sure that you have included the header file that contains the declaration for ListNode.
- Anatari
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Anatari wrote:
Make sure that you have included the header file that contains the declaration for ListNode
This is in the same file that the implementation of the list exists.
Nick Parker
May your glass be ever full.
May the roof over your head be always strong.
And may you be in heaven half an hour before the devil knows you’re dead. - Irish Blessing
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in the line:
<br />
ostream &operator << (ostream &strm, ListNode& *Node)<br />
are sure you didn't mean to write:
<br />
ostream &operator << (ostream &strm, ListNode& Node)<br />
Just trying to help even if i'm way off =)
- Anatari
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Anatari wrote:
Just trying to help even if i'm way off =)
I still get the same error.
Nick Parker
May your glass be ever full.
May the roof over your head be always strong.
And may you be in heaven half an hour before the devil knows you’re dead. - Irish Blessing
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I'd concur that a reference to a pointer is a bit funny. What is a ListNode ? Have you tried putting class ListNode; above the operator ?
Christian
No offense, but I don't really want to encourage the creation of another VB developer. - Larry Antram 22 Oct 2002
Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002
During last 10 years, with invention of VB and similar programming environments, every ill-educated moron became able to develop software. - Alex E. - 12-Sept-2002
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Christian Graus wrote:
Have you tried putting class ListNode;
Nope, but just did....AND IT WORKED! What is the purpose of doing a forward reference here? ( please explain ) I also switched it so that it was only passing a pointer not a reference to the pointer (it's getting late  ). Thanks Christian.
Nick Parker
May your glass be ever full.
May the roof over your head be always strong.
And may you be in heaven half an hour before the devil knows you’re dead. - Irish Blessing
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Hi,
I'm trying to get the address of the windows proc of a running application using:
WNDPROC AppWndProc = (WNDPROC)GetWindowLong(m_hWnd, GWL_WNDPROC);<br />
DWORD errVal = GetLastError();
The call to GetWindowLong fails (returns null) and the value returned from GetLastError() is 5, which is an access denied result.
I'm not sure if i'm missing something, but how is it that this application is preventing me from getting this address ? Is there some way to prevent people from using GetWindowLong ? I want to subclass this app so that when a user moves it i can be notified as well.
Thanks
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Are you in a separate process? If so you will need to do something else to get your DLL loaded in their process. Any address that is returned to you by this function will only be valid in the process that contains the window.
Your problem may be related to that fact, but I am not certain.
Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!
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Hi,
I posted this before, but no one responded. 
I'm new to C ++/mfc and I'm trying to modify a chat program to have the capability to transfer files as well as messages.
I found help from with code to send the file from this forum, but when I implemented it, I keep getting an error, "Unknown error while accessing unnamed file".
I put a button on the client side, and when the person clicks on it, the file dialog box is supposed to open, and the person can choose the file to send.
I get the dialog box, but I get the error right after I choose the file.
I put messages throughout the code to see where the program has reached, and it seems to be going through fine! It's also reading the data!
I'm really confused!!
I'm pasting the code below. If anyone has any idea what I'm doing wrong please respond.
-------------------------------------------------
void CMainFrame::OnSFile()
{
MessageBox("File Transfer");
CSocket cSocket;
cSocket.Create();
cSocket.Connect((LPCTSTR(m_strServerIP)),m_iFTPort);
csocketfile sf(&cSocket);
CArchive ar(&sf, CArchive::store);
/*code for CFileDialog goes here*/
static char BASED_CODE szFilter[] = "All Files (*.*)|*.*||";
CString strPath;
CFileDialog m_ldFile(TRUE,".*","*.*",OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT, szFilter);
// Initialize the starting directory
//m_ldFile.m_ofn.lpstrInitialDir = _T("C:\\");
// Show the file open dialog and captures the result
//if IDOK
if (m_ldFile.DoModal() == IDOK)
{
strPath = m_ldFile.GetPathName();
CFile myFile(strPath,
CFile::modeRead | CFile::typeBinary);
MessageBox("here");
//get file info
DWORD length = myFile.GetLength();
MessageBox("here2");
char *data = new char[length];
MessageBox("here3");
myFile.Read(data, length);
MessageBox("here4");
//send it across
ar << myFile.GetFileName();
ar << length;
ar.Write(data, length);
delete[] data;
myFile.Close();
}
MessageBox("here5");
}
----------------------------------------------------------------
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Pett wrote:
I'm new to C ++/mfc and I'm trying to modify a chat program to have the capability to transfer files as well as messages.
If you're really new to C++, you need to forget MFC and Windows, and do some console programming until you've had a chance to learn the core language properly.
Do you know how to use the debugger ? Do you know what line is breaking ? Do you know if you have a connection first ?
Christian
No offense, but I don't really want to encourage the creation of another VB developer. - Larry Antram 22 Oct 2002
Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002
During last 10 years, with invention of VB and similar programming environments, every ill-educated moron became able to develop software. - Alex E. - 12-Sept-2002
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Thank you for responding. 
I actually have to do this for an assignment in one of my MSc classes.. Networking. So, I have no choice but to dive into everything at once..
Also, I have tried putting messages in the code to see if the program is actually reaching that part of the code... and it goes through fine... then I get the error.
I'm not sure if I'm using debugger properly, but I put a break point at several places, and it went through again... then the error.
I showed this to my professor yesterday, and he said it was puzzeling as well.
You asked if I had a connection. You mean to the server right? Yes I do...
If I am sending a file, but there is no receiving code on the server side, what will happen?
I'm wondering now if it is my sending that is the problem. Maybe I'm not doing something with CArchive...
Thanks a lot for your input.
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i have the process id and its name and i want to get
GUITHREADINFO object.for that purpose i have to call
GetGUIThreadInfo where i have to put idThread value .
and my question is about idthread.
inorder to get idthread i have to call GetWindowThreadProcessId where i have to put hwnd and lpdwProcessId.
is idthread of each window of a process is different ?
mey i get GUITHREADINFO object using process id and its name using some other methods ?
because when i get GUITHREADINFO object it dose not have correct thread in it.
r00d0034@yahoo.com
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If you're using MFC, *this will give you the HWND.
Christian
No offense, but I don't really want to encourage the creation of another VB developer. - Larry Antram 22 Oct 2002
Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002
During last 10 years, with invention of VB and similar programming environments, every ill-educated moron became able to develop software. - Alex E. - 12-Sept-2002
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plz read question first then ans.
r00d0034@yahoo.com
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