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Hello everybody!
I have been encountering some difficulties with my applications and it constantly crashes. Lacking VC++ at the place of installment, it basically gives a dialog from the system stating a page fault has occurred.
The error could be a pointer pointing to NULL, moving ptrs to garbage areas, or anything..but the only information I get is a page faullt has occurred, which really isn't helpful.
Is there another way that will give more details about the error?
Cheers,
wilche
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You need to catch the exception and then print out a stack dump to let you know where it crashed. There are some debuggin libraries available on codeproject that will handle stack dumps.
Todd Smith
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Hi
i have an app i'm coding and it needs a standalone DataBase.
So i figure using jet engine via DAO...is there a better option?
cheers
bryce
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Yeah, most of them. Jet is hopelessly out of date and deprecated. Check out MSDE instead, it's a lite version of SQL Server.
Christian
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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coolo...
i shall investigate 
cheers
bryce
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Hi, I want 0xf2f2 to be displayed in a Messagebox, but what I got is a "?",
tell me how to accomplish this mission.
Appreciation
Extreme programming. Do the No.1
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this will convert an arbitrary stream of bytes to a CString:
CString HexDump(BYTE *pData, DWORD dwSize)
{
CString out;
for (DWORD i=0; i < dwSize; i++)
{
CString f;
if (pData[i] < 16)
f.Format("0%x", pData[i]);
else
f.Format("%x", pData[i]);
out+=f;
}
return out;
}
-c
Support regime change. Vote.
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I was looking at converting a project from VC6 to VC7.
Deep in the code something like this happens:
LPCTSTR szDesc; is passed into a function,
CString *pstrDesc = new CString();
...
...
(*pstrDesc) = szDesc;
This runs fine in VC6, but the memory management class in VC7 passes null pointers, which promptly crash.
I can find lots of info about how the CString class has changed, but nothing about how/whether code should be rewriiten/changed to deal with th new implementation.
Can anyone help with a fix/workaround? There are an awful lot of CStrings to convert to TCHARS before we can justify an upgrade to .net!!!!
Hugh
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are you testing for NULL on each "new" you do?
-c
Support regime change. Vote.
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The null is being passed, and crashing, inside the Microsoft code. The best I could do to detect it would be an exception handler!!!!
Hugh
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I attempted to reproduce this error but could not. If an instantiated CString object is assigned a NULL, it empties that object.
If a CString constructor fails due to insufficient memory, an exception will be thrown (I verified this.)
Something else is happening in your code. I suspect memory corruption before you even get to the "new CString()"
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The problem is so serious I expect it is something else in my code, my problem is what!
It appears to me that there is an error being passed from the memory management to the CString code. This is mostly MFC, and although I can step through it, I don't understand the logic behind it.
I have pushed up the error reporting on Bounds Checker and it reports nothing.
I am lost as to what is wrong, but as the code has been running without (reported) problems for over 3 years, under VC6, I am assuming something in the new MFC/template is less forgiving.
Does anyone know of a technical description of the changes in the CString class, between 6 and 7, which may give me a clue as to where to look?
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These kinds of bugs are among the most aggravating.
CString changed drastically between 6 and 7. The new CString is a typedef of CStringT which is derived from CSimpleStringT. Unfortunately, while I knew the old CString like the back of my hand, I am just getting acquainted with the new.
One thing to check for is a buffer overrun. The old CString used a fixed memory allocator pool which meant that depending on the size of the string, you could do a GetBuffer() then copy more data to the string than you had requested be allocated. Of course, this would usually be caught in debug mode, but it's worth a look.
(That your problem is with the memory points me in this general direction.)
My only other suggestion is to write a test program and break out chunks of code and test them in it. (And if my experience is normal, the test program will probably grow into a hideous monster, but it may help.)
And nothing beats just stepping through the code, line by line.
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What does this work
unsigned long (*array)[256];
array = new unsigned long[4][256];
and this does not
unsigned long* array[256];
array = new unsigned long[4][256];
error C2440: '=' : cannot convert from 'unsigned long (*)[256]' to 'unsigned long *[256]'
Todd Smith
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Compare this:
char* ptr;
char arr[10];
ptr = arr;
with
char* ptr;
char arr[10];
arr = ptr;
Static arrays can be seen as const pointers - static arrays can only point to what it was initialized with.
Basically the same thing going on with your error, with the difference that the error lies on another level of indirection.
--
Please state the nature of your medical emergency.
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Todd Smith wrote:
array = new unsigned long[4][256];
Is that even legal? I thought you could only allocate one-dimensional arrays with new.
But the difference bewteen the two declarations is the types.
unsigned long (*array)[256];
"array" is a pointer to an array of 256 long.
unsigned long* array[256];
"array" is an array of 256 long*
Totally different beasts.
--Mike--
Just released - 1ClickPicGrabber - Grab & organize pictures from your favorite web pages, with 1 click!
My really out-of-date homepage
Sonork-100.19012 Acid_Helm
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Is is possible to turn the following macro into a template? I'm unsure about the ##i.
#define S(x,i) (SBoxes[i][x.w.byte##i])
Todd Smith
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Working with the blowfish encryption ???
The ## operator with the proprocessor only works because it modifies the code before the compiler gets to it.
1) You could accomplish the same things but you will need to change the main data block union that is used to array notation and that would work.
2) Or you could change the bf_F macro to send in the name of the variable.
I would probably do the first suggestion if you dont like the macro syntax.
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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I'm not sure.
Templates needs to be figured out at compile time - not before and not after. Your piece of code is first transformed pre compile time (##-operator) and runtime - access of instance data.
Since x and i seem to be runtime data, this model would probably not work well using templates. However, I'm sure if you'd redo the whole model to suit templates there is most likely a solution.
--
Please state the nature of your medical emergency.
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Hello, Im trying to create a simple win32 application that will popup with a messagebox which shows the data a specific key in the registry.
The only thing I can't figure out is how to access the registry and dump the data in the key I need. I searched on MSDN.microsoft.com but I didn't find anything..
Thanks
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Read the 8th posting below this one.
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You can find several classes here in CP to Access the regsitry...
Regards
Carlos Antollini.
Sonork ID 100.10529 cantollini
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Ok. I had a post earlier about my app failing in release mode. Thanks, to some help on here, I thought I had it narrowed down to the MSFlexgrid.ocx control delivered with VS6. I have read and was told that to redistribute the control you must have a runtime license embedded in your application.
The wierd thing is that another developer that I work with was able to distribute his control on a PC w/o VS6 installed, and it worked. Blew me away. So, I duplicated what he did and it worked too.
The method? Ensure that the control is in your resource workshop toolbox by Project | Add To Project | Components and Controls. Once, it's there you must add it to your dlg or form view, using the class wizard so it will DDX it for you. U see, I sometimes don't use the class wizard since I was dynamically creating and deleting the grid controls and a tab control. I've changed this approach now to just statically use the controls and make visible/invisible what I don't want the user to see.
Apparently, this somehow embeds the license into it??? Cuz, I simply ran the install program (which only copies and registers the control) and it works fine, now.
Go figure!! Anybody know about why this works?
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What do you think of making a Boehm GC - Object Oriented framework for interacting with Windows?
LPCTSTR Dutch = TEXT("Double Dutch ");
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