|
Well to start with you can not do things like this:
LPDWORD lpNumberOfBytesRead = sizeof buf;
The variable lpNumberOfBytesRead is a pointer and a pointer holds the address of where the data is stored. What the above line is doing is setting the address to the value sizeof(buf), which is not an address.
Change to:
DWORD NumberOfBytesRead = sizeof(buf);
or this (since its initial value may not matter)
DWORD NumberOfBytesRead = 0;
and pass like this
SomeFunction(...,...,&NumberOfBytesRead);
Now the following from your code, should make any C++ compiler choke (fail with errors):
ReadProcessMemory(
hProcess,
lpBaseAddress,
nSize, // This should be a pointer to buffer
bufsize,
buff ); // This should be a pointer to DWORD
The correct arguments are
ReadProcessMemory( hProcess, lpBaseAddress, buf, bufsize, &NumberOfBytesRead);
or
ReadProcessMemory( hProcess, lpBaseAddress, buf, sizeof(buf), &NumberOfBytesRead);
I have no doudt that there are several other things wrong with this code, but the above should help you get started on figuring out what they are.
INTP
"The more help VB provides VB programmers, the more miserable your life as a C++ programmer becomes."
Andrew W. Troelsen
|
|
|
|
|
Yep i looked at that and there were mistakes, but the main problem comes from the virtualqueryEx function which has to do most of the things. Because i have to read pages using it...
So it gives this error msg:
"The value of ESP was not properly saved across a function call."
error code 5: Illegal function call
error code 998: from virtualqueryex function
oam
|
|
|
|
|
The code you gave should not compile on any compiler period! Let alone give any error messages when run. I can not remember ever seeing so many basic programming errors. If by some miricle it did run, then (Yep) it would probubly crash. Heck you stand a better chance of crashing the whole system than making that code work (as written).
As for VirtualQueryEx: Why are you even trying to call it? The call appears to be used to retrieve information that needs to be stored in the structure pointed to by lpBuffer, but lpBuffer does not point to a structure, it points to NULL. The only reason the dwLength argument is correct, is that it is 0, since lpBuffer is NULL. You are also passing it a 5th argument GetLastError, for who knows what reason (it only takes 4 arguments and this is not one of them).
I recomend you start all over again from scatch. What ever it is you are trying to accomplish, this will not do it.
P.S. Sorry but if I was an employer, the code you gave would get you fired.
INTP
"The more help VB provides VB programmers, the more miserable your life as a C++ programmer becomes."
Andrew W. Troelsen
|
|
|
|
|
See title , thanks..
Couldn't find the functions using MSDN or google .
|
|
|
|
|
GetFileAttributes(), check the FILE_ATTRIBUTE_DIRECTORY bit.
"You're obviously a superstar." - Christian Graus about me - 12 Feb '03
"Obviously ??? You're definitely a superstar!!!" mYkel - 21 Jun '04
Within you lies the power for good - Use it!
Honoured as one of The Most Helpful Members of 2004
|
|
|
|
|
bool dirExists
(CString strDirectory)
{
TCHAR* fullPath = _tfullpath (NULL, strDirectory, 0);
if (fullPath == NULL)
return (false);
TCHAR szCurrDir [_MAX_PATH];
_tgetcwd (szCurrDir, _MAX_PATH - 1);
long nStatus = _tchdir (fullPath);
_tchdir (szCurrDir);
free (fullPath);
if (nStatus == 0)
return (true);
return (false);
}/ravi
My new year's resolution: 2048 x 1536
Home | Articles | Freeware | Music
ravib@ravib.com
|
|
|
|
|
|
We have a driver for low level control for the parallel port using outp inp. However, this driver only works on NT platforms under Administrator. I am trying to find a way to tell the manager that the user has permissions to run this driver.
However, I cannot get access to the manager from my level to do that. How can I change the rights for the program to run under any user?
here is a snipit of code that I have.
// connect to local service control manager
if ((m_hSCMan = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS)) == NULL)
{
AfxMessageBox("Can't connect to service control manager\n\nI am assuming that you are working on a non-NT system.\n\nIf not you will need to investigate the problem", MB_OK);
m_fNT = FALSE;
}
else
{
if (DriverStart(szDriver))
{
AfxMessageBox("Unable to start the driver!\n\n"
"Please try running [loaddrv] to correct this issue.", MB_OK);
}
}
|
|
|
|
|
in my app, i open a html file and get its buffer in memory, is it possible to display the file buffer as a normal html page?
the html file is inside a zipped file, so it can not be desplayed directly.
thanks
includeh10
|
|
|
|
|
includeh10 wrote:
is it possible to display the file buffer as a normal html page?
Yes. See this[^] article.
/ravi
My new year's resolution: 2048 x 1536
Home | Articles | Freeware | Music
ravib@ravib.com
|
|
|
|
|
Hello.
my problem is that i'm loading a dll to extract some data but it gets lost when i unload the library, i have the following struct
<br />
struct tagPLUGIN{<br />
PCHAR Name;<br />
PCHAR FileName;<br />
UINT Category;<br />
UINT Vital;<br />
ULONG Id;<br />
UINT isUI; <br />
};
and from my main exe i just load the library, get the proccess address and call a dll function to fill the structure
<br />
extern "C" __declspec(dllexport) void GetPlugInfo (tagPLUGIN *plugin)<br />
{<br />
<br />
AFX_MANAGE_STATE(AfxGetStaticModuleState());<br />
plugin->Category=TOOL;<br />
plugin->Id=0;<br />
plugin->isUI=TRUE;<br />
plugin->Name=new char[25];<br />
strcpy(plugin->Name,"Configuración de Sistema\0");<br />
plugin->Vital=FALSE;<br />
}<br />
loading the dll
<br />
tagPLUGIN plugin;<br />
typedef void (*GetPlugInfo)(tagPLUGIN *info);<br />
HMODULE dll=LoadLibrary(tmp_string);<br />
GetPlugInfo getPlugInfo = (GetPlugInfo)GetProcAddress(dll,"GetPlugInfo");<br />
(getPlugInfo)(&plugin);<br />
plugin.Id=ID++;<br />
plugin.FileName=new char[tmp_string.GetLength()+1];<br />
strcpy(plugin.FileName,tmp_string.GetBuffer());<br />
FreeLibrary(dll);<br />
but right after FreeLibrary(dll) my two PCHAR values are corrupt, i know the problem is in the new char[size], so how can i pass a PCHAR to a dll function and allocate and assign a string without loosing it after freelibrary?
|
|
|
|
|
you could do the allocation in the calling module, not in the DLL. or, just use a fixed-size buffer for the text in the structure.
or, use global memory (ie. GlobalAlloc, etc) to allocate the strings.
Image Toolkits | Image Processing | Cleek
|
|
|
|
|
Hi Chris,
no it doesn't, i was trying to with HeapAlloc, but both after i call FreeLibrary(dll)
i get a <bad ptr=""> value.
By the way, why it works in debug mode?
anybody can give me links of dll tutorials/guides please.
Best Regards
|
|
|
|
|
Your dll, and or exe, is likely being staticly linked to the CRT.
That is, the dll new, malloc, alloc, calloc functions are using a heap local to the dll.
When the dll is unloaded the heap is destroyed.
The debug version is likely set to dynamicly link to the CRT so the exe and dll use the same heap for memory allocations.
...cmk
Save the whales - collect the whole set
|
|
|
|
|
Tthanks for your help.
No, i'm using both debug and release in shared dll, the dll and exe both debug uses debug and release uses release, i've tried, new,malloc,GlobalAlloc and Heap Alloc, same result.
i'll do some more reading about dlls and retry this, but for now i have an idea, can you tell me if this could be the good way:
near that code i have some code to read from the registry and i've noted that when in RegQueryValueEx you pass a buffer too small for the required data (REG_SZ) it returns the size of the buffer needed so you can reallocate the memory for the buffer with that size, so i'll code my GetPlugInfo in that way and i'll pass the PCHAR vars with the memory preallocated. Is that a good solution?
Thanks in advance.
|
|
|
|
|
I'm not sure that you understood what i was talking about.
In VC++
Goto Projects - Settings.
Goto C/C++ - Code Generation.
For both your exe and dll the 'Use run-time library' should be:
'Debug Multithreaded DLL' for your debug builds.
and
'Multithreaded DLL' for your release builds.
There is no reason you can't do what you originally specified.
...cmk
Save the whales - collect the whole set
|
|
|
|
|
Hi,
I want to use arrow key to move focus among dialog controls. But standard dialog does not support this. How can i do it? is there a sample code?
best regards,
|
|
|
|
|
li0000 wrote:
I want to use arrow key to move focus among dialog controls. But standard dialog does not support this.
Yes it does, you just have to set the WS_GROUP styles right. Identify what group of controls (checkboxes, buttons, radio buttons, etc.) you want to move through. Make sure they're in the right tab order. Set the WS_GROUP style on the first control in the group, and unset the style on the remaining controls.
--Mike--
LINKS~! Ericahist updated! | 1ClickPicGrabber | CP SearchBar v2.0.2 | C++ Forum FAQ
Strange things are afoot at the U+004B U+20DD
|
|
|
|
|
Hi Mike
How about CEdit and CComBoBox control? Can I also use this method to implement navigating using arrow keys?
Thanks
|
|
|
|
|
Window Styles
WS_GROUP Specifies the first control of a group of controls in which the user can move from one control to the next with the arrow keys. All controls defined with the WS_GROUP style FALSE after the first control belong to the same group. The next control with the WS_GROUP style starts the next group (that is, one group ends where the next begins).
|
|
|
|
|
Dear gurus,
I am required to write a C++ library program using Visual C++ 6.0.
The criterias are:
1)Create 2 output .dat files one for the library book database and the other for borrowers list and books that are leased.
The first file will list:
Book Title Date added Author Publisher Avilbility status
The second file will list:
Name of borrower Book borrowed Date borrowed Expiry Date
2)The menu of the program should have:
a)Review books database and availability
b)Review/List borrowers/books borrowed
c)Add/alter books list
d)Add/Remove borrowers from the list
Need help ASAP.Only had 2 months experience with C++.Currently I only know how to create classes,make switch statements,arrays,structures and loops.Still not very familiar with I/O writing/reading.I am having headache on how to relate all of them.Another question is how do I individually remove the data from the database one by one specifically?I know how to write a list and add but let's say member #3 already returns his book how to remove him from the list and change the book availability status in the other file to available again?
Thanks in advanced.
|
|
|
|
|
As most of us here only help with understanding and small tidbits of code, you probably won't find your completed project, but here is a couple of pointers (no pun intended  ):
Adding items is easy: just append each item at the end of the list, then save just the appended data to the file. However, when you remove the items, depending on where it is in the file, you will have to remove the item and shift everything after it back 1 spot. Since you don't have a lot of programming experience, I suggest this: load the list into memory and do all the processing there. Each add will add to the list to memory, and append the item to the file. Each remove, however, will remove the item from memory and rewrite the file from scratch.
I know this process is can be slow when there are a lot of items, but its a surefire way to make it work. The other alternative is figure out some way to use ODBC or some other SQL server, which have much more efficient ways of inserting and removing items from databases.
Hope this helps you out a little. Happy coding!
|
|
|
|
|
Hello,
I have an application that uses CSocket and I am trying to put
the socket I/O into a thread.
I tried to put it into a non-derived-class worker thread, but
this clearly doesn't work, in that the program crashes.
I tried to create a derivative of CWinThread but that compiled
but didn't link, because it cannot find the runtime class info.
Can someone point me to an example of a program that puts
socket I/O in a thread successfully?
Thanks.
|
|
|
|
|
|
That article deals with passing a socket to a thread.
What I'm trying to do is create the socket inside the thread.
I can detect that the thread is being run, but the moment
I call Create, it crashes the program.
I get the following stack :
CMapPtrToPtr::GetValueAt(void * 0x00000744) line 179 + 3 bytes
CAsyncSocket::LookupHandle(unsigned int 0x00000744, int 0x00000000) line 385 + 15 bytes
CAsyncSocket::AttachHandle(unsigned int 0x00000744, CAsyncSocket * 0x00de7cf0 {CSocket}, int 0x00000000) line 407 + 13 bytes
CAsyncSocket::Socket(int 0x00000001, long 0x0000003f, int 0x00000000, int 0x00000002) line 557
CAsyncSocket::Create(unsigned int 0x00000000, int 0x00000001, long 0x0000003f, const char * 0x00000000) line 105 + 20 bytes
CSocket::Create(unsigned int 0x00000000, int 0x00000001, const char * 0x00000000) line 45 + 29 bytes
CMyThread::MyMessageHandler(unsigned int 0x00000401, long 0x00aa1180) line 570 + 17 bytes
CWinThread::DispatchThreadMessageEx(tagMSG * 0x00aa10c4 {msg=0x00000401 wp=0x00000401 lp=0x00aa1180}) line 652
CWinThread::PreTranslateMessage(tagMSG * 0x00aa10c4 {msg=0x00000401 wp=0x00000401 lp=0x00aa1180}) line 660 + 20 bytes
CWinThread::PumpMessage() line 841 + 30 bytes
CWinThread::Run() line 480 + 11 bytes
_AfxThreadEntry(void * 0x0011deec) line 125 + 11 bytes
_threadstartex(void * 0x00aa2f80) line 212 + 13 bytes
KERNEL32! 7
|
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
