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I'm having some nasty problems with the MFC class CFileDialog. I'm simply trying to use it to get the name of a selected file and put it in a text edit box. I have done this many times before and have never had this sort of problem. Here is the code that is producing the error:
[code]
void CFileSplitterDlg::OnButtonOpenSplitFile()
{
CFileDialog FileOpen(TRUE,0,0,OFN_HIDEREADONLY|OFN_OVERWRITEPROMPT,0,this);
FileOpen.m_ofn.lpstrTitle="Select File to Split";
int Result=FileOpen.DoModal();
if (Result==IDOK)
{
SetDlgItemText(IDC_EDIT_SPLIT,FileOpen.GetPathName());
m_ProgressSplit.SetPos(0);
}
else
{
if (Result==IDCANCEL)
{
SetDlgItemText(IDC_EDIT_SPLIT,"");
}
}
}
[/code]
IDC_EDIT_SPLIT is defined, and m_ProgressSplit is a valid member variable. I also looked up on the MSDN anything I could find on CFileDialog and access violations and found something regarding custom CFileDialog classes and access violations, the issue is apparently fixed in windows 2000 (I'm running XP Pro), and is also fixed in VS6SP6 (I was running VS6 with no service pack when I encountered this error, I have since upgraded to SP6, this of course did not help), so I'm pretty sure it's not that I'm missing anything. Originally I was using MFC dlls, I tried switching to static MFC libraries to see if that had any effect, it didn't. I also tried created a brand new dialog based MFC application and made it so the only thing it did was create a CFileDialog when the default 'OK' button was pressed. I got the same error (which leads me to believe it is not something isolated to my project).
I've narrowed it down to the destructor of CFileDialog. When I press the 'Open Split File' (which calls CFileSplitterDlg::OnButtonOpenSplitFile()) button the CFileDialog is created and DoModal() is called (causing the dialog to appear). It then lets me select a file. If I press 'Open' it returns IDOK and the file name gets put into the text edit box. If I select 'Cancel' IDCANCEL is returned and anything inside the text edit box is cleared (as it should be). The error doesn't occur untill the destructor is called. Which of course happens when the CFileDialog goes out of scope as soon as the function. Everything I have before then works correctly (I used message boxes to stop determine the point just before it crashes). I even commented out everything but the constructor and still got an error when the destructor is called.
The error message it says when the program crashes when I run it through the debugger says, "Unhandled exception in File Splitter.exe (KERNEL32.DLL): 0xC0000005: Access Violation."
Here is the call stack the debugger gives me.
[code]
KERNEL32! 77e778ce()
CFileDialog::~CFileDialog() + 71 bytes
CFileSplitterDlg::OnButtonOpenSplitFile() line 198 + 18 bytes
_AfxDispatchCmdMsg(CCmdTarget * 0x0012fd74 {CFileSplitterDlg}, unsigned int 1007, int 0, void (void)* 0x00401078 CFileSplitterDlg::OnButtonOpenSplitFile(void), void * 0x00000000, unsigned int 12, AFX_CMDHANDLERINFO * 0x00000000) line 88
CCmdTarget::OnCmdMsg(unsigned int 1007, int 0, void * 0x00000000, AFX_CMDHANDLERINFO * 0x00000000) line 302 + 39 bytes
CDialog::OnCmdMsg(unsigned int 1007, int 0, void * 0x00000000, AFX_CMDHANDLERINFO * 0x00000000) line 97 + 24 bytes
CWnd::OnCommand(unsigned int 1007, long 2818546) line 2099
CWnd::OnWndMsg(unsigned int 273, unsigned int 1007, long 2818546, long * 0x0012f82c) line 1608 + 28 bytes
CWnd::WindowProc(unsigned int 273, unsigned int 1007, long 2818546) line 1596 + 30 bytes
AfxCallWndProc(CWnd * 0x0012fd74 {CFileSplitterDlg hWnd=???}, HWND__ * 0x00a3027a, unsigned int 273, unsigned int 1007, long 2818546) line 215 + 26 bytes
AfxWndProc(HWND__ * 0x00a3027a, unsigned int 273, unsigned int 1007, long 2818546) line 379
USER32! 77d67b17()
USER32! 77d6cdce()
USER32! 77d45696()
USER32! 77d461f6()
USER32! 77d5ec02()
USER32! 77d5c3f6()
USER32! 77d67b17()
USER32! 77d6cdce()
USER32! 77d44435()
USER32! 77d49611()
USER32! 77d5d704()
CWnd::IsDialogMessageA(tagMSG * 0x005f58dc {msg=0x00000202 wp=0x00000000 lp=0x00060017}) line 182
CWnd::PreTranslateInput(tagMSG * 0x005f58dc {msg=0x00000202 wp=0x00000000 lp=0x00060017}) line 3435
CDialog::PreTranslateMessage(tagMSG * 0x005f58dc {msg=0x00000202 wp=0x00000000 lp=0x00060017}) line 92
CWnd::WalkPreTranslateTree(HWND__ * 0x00a3027a, tagMSG * 0x005f58dc {msg=0x00000202 wp=0x00000000 lp=0x00060017}) line 2678 + 18 bytes
CWinThread::PreTranslateMessage(tagMSG * 0x005f58dc {msg=0x00000202 wp=0x00000000 lp=0x00060017}) line 672 + 18 bytes
CWinThread::PumpMessage() line 848 + 30 bytes
CWnd::RunModalLoop(unsigned long 4) line 3489 + 19 bytes
CDialog::DoModal() line 539 + 12 bytes
CFileSplitterApp::InitInstance() line 52 + 11 bytes
AfxWinMain(HINSTANCE__ * 0x00400000, HINSTANCE__ * 0x00000000, char * 0x00141f3c, int 1) line 39 + 11 bytes
WinMain(HINSTANCE__ * 0x00400000, HINSTANCE__ * 0x00000000, char * 0x00141f3c, int 1) line 30
WinMainCRTStartup() line 198 + 54 bytes
KERNEL32! 77e7eb69()
[/code]
And here is a disassembly immediately surrounding the code that execution stops on.
[code]
77E778BE xor eax,eax
77E778C0 jmp 77E77554
77E778C5 mov ecx,dword ptr [esp+4]
77E778C9 mov eax,0FFFFFFFFh
77E778CE lock xadd dword ptr [ecx],eax
77E778D2 dec eax
77E778D3 ret 4
[/code]
It apparently stops on 77E778CE. It would appear that the pointer in ecx is a bad pointer (NULL or outside the program's memory space). I'm not 100% sure what lock xadd does, I googlged for it and it appears to have to do with threads and making it so another thread can't mess upo a counter of somekind. I'm wondering why it doesnt crash on 77E778C5... or is all that happens there is the value pointed to on the stack pointer+4 being put into ecx and that is used as a pointer? I'm not good with pointers in assembly (I don't know the syntax well enough) so I don't know if I really know what I'm talking about.
Either way it seems like it ends up with an invalid pointer. My biggest question is why? I have not done anything out of the ordinary. I followed all the examples I've found that use CFileDialog (even the one on MSDN) exactly as they were presently (sans a few minor changes that shouldn't cause an error like this). I don't understand why it used to work and now it doesn't (in any new or old project).
Any help on this would be grealty appreciated. I'm at a total loss here. This far exceeds my ability...
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This seems very strange.  One suggestion is check the packing of the project with one that works. There can be some quite strange side effects with packing. Normally projects default to 8 byte alignment.
Ant.
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I Use them to Make Multilingual interface for my programm(LoadLibrary(),AfxSetResourceHandle()), But i want to have in my menu options to change interface dinamically. How to update all views after calling AfxSetResourceHandle()???
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I'm a C/C++ programmer. I want to learn Window programming. One of my friends suggested me to study SDK (petzold's book) first and then move to MFC.He told me by reading petzold's famous book "progamming windows" I will have my basic concept regarding windows cleared.
now .Net has come. Does .net have changed the idea behind windows programming. so is it worth to read petzold first or directily move to VC++ .net?...i want to learn it as soon as possible...
plz help me....
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Well, i cant say about .NET yet, but the petzold book is a worth buy. It will help you to grasp all of VC++ (though it doesnt include Directx, COM, etc). Petzold teaches you VC++ as WINDOWS API (not MFC  ). "Windows API" is definitely a stronger way to program Windows. Also it provides much more flexibility than MFC.
If you want to master windows programming, this is the best book available in the market. Also once u have learned the API, u can easily learn MFC(concepts are mostly same).
COM, OLE ald things like that can be implemented better(easily) via MFC.
Go fo it....
Remember... testing & debugging are always part of programming ...so exterminate those stinking bugs 
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My 2 cents worth; COM is better implemented via ATL, Windows apps are better implemented with WTL rather than MFC. Whichever of WTL or MFC you use, a thorough grounding of the API does absolutely no harm whatsoever. Knowing what's happening under the lid of any framework should mean you can make better use of whatever it is.
Steve S
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thanx avenger for ur suggestion bout windows programming....
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Here is my unresolved problem: I spoke about it last Friday but I have still no solutions for resolving it:
Description of the problem:
I use a function "PESDEMUX_ProcessFile" which is defined in the file "XtlPes.dll". This function allows me to convert file from one type to another.
I work on a device which is controled by my computer with the SERIAL or the USB port.
When I am on SERIAL Mode for controling the device, I have to transfer the file by USB port from the device to my computer and the function "PESDEMUX_ProcessFile" does the conversion. (I have to open and close a USB communication port for that). Here is there no problems.
Now, when I am on USB Mode for controling the device, I have to transfer the file by USB port too from the device to my computer and the function "PESDEMUX_ProcessFile" may does the conversion too. But I have a Visual C++ error: "Unhandled exception in Appli.exe (XTLPES.DLL): 0xC0000005: Access Violation." With the "Call Stack" option in Visual C++, I see that there is a problem at that line: "00E34F3D mov eax,dword ptr [esi+304h]".
Here is the code I used for caling the function "PESDEMUX_ProcessFile":
typedef LONG (__cdecl *PESDEMUX_ProcessFile)(CHAR*,CHAR*,INT);
PESDEMUX_ProcessFile pProcessFile;
CHAR chInFileName[255];
strcpy(chInFileName, m_csPCFileName); //Conversion CString to CHAR*
CHAR chOutFileName[255];
m_csPCFileName = m_csPCFileName + ".mpg";
strcpy(chOutFileName, m_csPCFileName); //Conversion CString to CHAR*
INT Type = 1;
if (theApp.g_hDllXtlPes != NULL)
{
pProcessFile = (PESDEMUX_ProcessFile)GetProcAddress(theApp.g_hDllXtlPes,"PESDEMUX_ProcessFile");
if (!pProcessFile)
{
FreeLibrary(theApp.g_hDllXtlPes);
return FALSE;
}
else
{
BOOL BResult = TRUE;
BResult = pProcessFile(chInFileName,chOutFileName,Type);
if (BResult == FALSE)
{
TRACE("Conversion Process OK\n");
}
else
TRACE("Conversion Process non OK\n");
}
}
With HINSTANCE g_hDllXtlPes = LoadLibrary("XtlPes.dll"); defined in another .cpp file.
Do you have any ideas on that curious problem ?
Thank's for advance,
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Do u really think it helps when you ask two times?
I've read the last article and I won't read it again.
Don't try it, just do it! 
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You really are not the most helpful person, Alexander
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It's a hard problem and I need to solve it as soon as possible...
But nobody can help me...
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A possibility may be that you ha ve No Access priveleges in windows NT related. I got the same problem trying to access paralle port using the _outp function. You probably have the same problem, but no garantee here.
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I'm trying to create a simple application using C++ and MFC that is able to retrieve some hardware & general information of my pc and show it on the screen rather than having to check manually.
Examples of information to be retrieved include:
-Machine Name, Date Created, IP address of my pc, Memory, Users, Last Logon, Last Logoff and etc
1) How to get all this information thr C++ codes?
2) Any website that provide relevant codes or samples?
Best Regards,
xiAoYJia
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I can remember some articles about that on CP, search...!
Don't try it, just do it!
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Hey, the following page provides you with more than enough information. Just select the functions of your choice and see the SYNTAX. All these are WINDOWS API (VC++) functions. They can of course be used in console mode C++ programs compiled under Visual Studio5.0 or above.
Link::
System Information functions at MSDN, microsoft(http://msdn.microsoft.com/library/default.asp?url=/library/en-us/sysinfo/base/system_information_functions.asp)
A few functions are namely GetComputerName, GetCurrentHwProfile, GetSystemInfo, GetSystemMetrics(Very Important ), GetUserName, SystemParametersInfo etc. etc. etc.
Remember... testing & debugging are always part of programming ...so exterminate those stinking bugs
...avenger
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How to check if the IE's Address Bar has got the focus in VC++ program : O.S Windows98
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Im new to VC7, and Im getting link errors that can be fixed using "project" -> "settings" in VC6.0 and linking the appropriate .lib file but how is it done in VC7
We have a mathematician, a different kind of mathematician, and a statistician!
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will this help
#pragma comment(lib,"libname.lib")
MSN Messenger.
prakashnadar@msn.com
"If history isn't good, just burn it." - Sidhuism.
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That did the trick,
Thanks a million.
We have a mathematician, a different kind of mathematician, and a statistician!
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How do I disable a net adapter? thanks in advance!
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net stop <servicename>
MSN Messenger.
prakashnadar@msn.com
"If history isn't good, just burn it." - Sidhuism.
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are u sure?
net stop stops a service, so if there are 2 (e.g.) realtek cards they will both stop.
Don't try it, just do it!
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hi guys,
I found that every program I wrote it require attach .dll files and the file after compile is very big (static dll), but some programe is very small, I wonder how can they do to decrease kb ?
thanks.
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Huu Tu wrote:
very big (static dll), but some programe is very small
Learn to program in ATL
C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do, it blows away your whole leg
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