passing structures across processes - C / C++ / MFC Discussion Boards

memory conflict on Win2000 and WinXP

ppp00125-Mar-04 21:19

25-Mar-04 21:19

Hi all,

I have written an application with a third party dll but get a
assertion fail from the third party dll,

The assertion fail on :
dbgheap.c and expression _CrtlsValidHeapPointer(pUserData)
it seems a memory conflict error

But the memory conflict error only occur on Window 2000, but on Window XP
Home it works fine, why ?

Re: memory conflict on Win2000 and WinXP

Tim Smith26-Mar-04 4:28

Tim Smith

26-Mar-04 4:28

Because the memory layout for XP and 2000 are slightly different. Someone has a bug in their program. They are deallocating an invalid pointer.

Tim Smith

I'm going to patent thought. I have yet to see any prior art.

Re: memory conflict on Win2000 and WinXP

ppp00126-Mar-04 7:39

ppp001

26-Mar-04 7:39

Thanks Tim,

What does the "invalid" of invalid pointer mean ?
1. a pointer which has already been deallocated
2. a pointer that has not been allocating memory yet
3. or something else ?

Patrick

CScrollView

Member 95412325-Mar-04 21:02

Member 954123

25-Mar-04 21:02

Hi,
I am merging 5 bmp's and displaying them as a single bmp in the OnDraw(). The bmp does not get scrolled when i move the

scrollbar.Instead if i draw a rectangle it gets scrolled when i move the scrollbars, why does not the bmp get scrolled?

Thanks and regards,
Salil.

void CAprsView::OnDraw(CDC* pDC)
{
CAprsDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
// TODO: add draw code for native data here

CString szFilename("d:\\vc\\mfc\\2001.bmp");
HBITMAP hBmp = (HBITMAP)::LoadImage(NULL,szFilename,
IMAGE_BITMAP,0,0,
LR_LOADFROMFILE|LR_CREATEDIBSECTION);
CBitmap bmp;
bmp.Attach(hBmp);
CClientDC dc(this);
CDC bmDC;
bmDC.CreateCompatibleDC(&dc);
CBitmap *pOldbmp = bmDC.SelectObject(&bmp);
BITMAP bi;
bmp.GetBitmap(&bi);
dc.StretchBlt (0,0,len_in_pix,ht_in_pix,&bmDC,0,0,bi.bmWidth
,bi.bmHeight,SRCCOPY);
bmDC.SelectObject(pOldbmp);

CString szFilename1("d:\\vc\\mfc\\2002.bmp");
HBITMAP hBmp1 = (HBITMAP)::LoadImage(NULL,szFilename1,
IMAGE_BITMAP,0,0,
LR_LOADFROMFILE|LR_CREATEDIBSECTION);
CBitmap bmp1;
bmp1.Attach(hBmp1);
CClientDC dc1(this);
CDC bmDC1;
bmDC1.CreateCompatibleDC(&dc1);
CBitmap *pOldbmp1 = bmDC1.SelectObject(&bmp1);
BITMAP bi1;
bmp1.GetBitmap(&bi1);
dc1.StretchBlt (0,br_in_pix,len_in_pix,ht_in_pix,&bmDC1,0,0,bi.bmWidth
,bi.bmHeight,SRCCOPY);
bmDC1.SelectObject(pOldbmp1);

CString szFilename2("d:\\vc\\mfc\\2003.bmp");
HBITMAP hBmp2 = (HBITMAP)::LoadImage(NULL,szFilename2,
IMAGE_BITMAP,0,0,
LR_LOADFROMFILE|LR_CREATEDIBSECTION);
CBitmap bmp2;
bmp2.Attach(hBmp2);
CClientDC dc2(this);
CDC bmDC2;
bmDC2.CreateCompatibleDC(&dc2);
CBitmap *pOldbmp2 = bmDC2.SelectObject(&bmp2);
BITMAP bi2;
bmp2.GetBitmap(&bi2);
dc2.StretchBlt (0,br_in_pix+ht_in_pix,len_in_pix,br_in_pix,&bmDC2,0,0,bi.bmWidth
,bi.bmHeight,SRCCOPY);
bmDC2.SelectObject(pOldbmp2);

CString szFilename3("d:\\vc\\mfc\\2004.bmp");
HBITMAP hBmp3 = (HBITMAP)::LoadImage(NULL,szFilename3,
IMAGE_BITMAP,0,0,
LR_LOADFROMFILE|LR_CREATEDIBSECTION);
CBitmap bmp3;
bmp3.Attach(hBmp3);
CClientDC dc3(this);
CDC bmDC3;
bmDC3.CreateCompatibleDC(&dc3);
CBitmap *pOldbmp3 = bmDC3.SelectObject(&bmp3);
BITMAP bi3;
bmp3.GetBitmap(&bi3);
dc3.StretchBlt (0,2*br_in_pix+ht_in_pix,len_in_pix,ht_in_pix,&bmDC3
,0,0,bi.bmWidth,bi.bmHeight,SRCCOPY);

bmDC3.SelectObject(pOldbmp3);

CString szFilename4("d:\\vc\\mfc\\2005.bmp");
HBITMAP hBmp4 = (HBITMAP)::LoadImage(NULL,szFilename4,
IMAGE_BITMAP,0,0,
LR_LOADFROMFILE|LR_CREATEDIBSECTION);
CBitmap bmp4;
bmp4.Attach(hBmp4);
CClientDC dc4(this);
CDC bmDC4;
bmDC4.CreateCompatibleDC(&dc4);
CBitmap *pOldbmp4 = bmDC4.SelectObject(&bmp4);
BITMAP bi4;
bmp4.GetBitmap(&bi4);
dc4.StretchBlt (0,2*br_in_pix+2*ht_in_pix,len_in_pix,20,&bmDC4
,0,0,bi.bmWidth,20,SRCCOPY);

bmDC4.SelectObject(pOldbmp4);
}

void CAprsView::OnInitialUpdate()
{
CScrollView::OnInitialUpdate();
// TODO: calculate the total size of this view

CSize sizeTotal(2000,3000);
CSize sizePage(sizeTotal.cx/2,sizeTotal.cy /2);
CSize sizeLine(sizeTotal.cx/2,sizeTotal.cy /2);
// TODO: calculate the total size of this view
//sizeTotal.cx = sizeTotal.cy = 100;
SetScrollSizes(MM_TEXT, sizeTotal,sizePage,sizeLine);
}

Query Service , Help required!!!!

rohit.dhamija25-Mar-04 20:48

rohit.dhamija

25-Mar-04 20:48

Dear All,

I am developing an application for Windows 2000 NTFS file systems using VC++ MFC version 6.0. I need to query whether "Norton antiviral" is installed on a system or not.

We know that Norton Antivirus runs as a service. So to find its existence I suppose, I should query whether the service for Norton exists of not in the system. So my query is that
"Is there any API provided to know existence of a service given its name. (In this case, navapscv is the name of the service, also we know its rest of parameters like display nameless)"

Or, is there any alternate way to accomplish the same task?

Please let me know if you need further clarification in this regards,

Regards,
Rohit

Re: Query Service , Help required!!!!

22491725-Mar-04 22:05

224917

25-Mar-04 22:05

try to open the service

SC_HANDLE OpenService(
SC_HANDLE hSCManager, // handle to SCM database
LPCTSTR lpServiceName, // service name
DWORD dwDesiredAccess // access
);

this function returns

ERROR_INVALID_NAME
ERROR_SERVICE_DOES_NOT_EXIST

not sure which one exactly

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How to declare 2d vector and insert data...

Ming Yan25-Mar-04 20:23

Ming Yan

25-Mar-04 20:23

Hi...

I'm still having problems with vectors. Can somebody provide me with d correct code that can b guaranteed to both of d above? Confused | :confused:

Thank you.

passing structures across processes

Raghunandan S25-Mar-04 20:02

Raghunandan S

25-Mar-04 20:02

Hi All,
I have a structure of CString variabls.I need to pass this variable from one application to other application.I was trying WM_COPYDATA message to pass the data but i'm unable to receive the structure in the destination process.can someone help me out in this.

my code looks like this

typedef struct
{
CString name;
Cstring job;
} Raghu;

Raghu raghu;
raghu.name = "Raghu";
raghu.job = "none";

COPYDATASTRUCT datastruct;
datastruct.lpdata = (void*)&raghu;
datastrcut.cbdata=raghu.name .getlength() + raghu.job.getlength();//is this correct way??

::SendMessage(HWND_BROADCAST, WM_COPYDATA, (WPARAM)this->GetSafeHwnd(), (LPARAM)&datastruct);

Thanks in advance

Re: passing structures across processes

El'Cachubrey25-Mar-04 20:32

El'Cachubrey

25-Mar-04 20:32

You can't pass pointers between process WM_COPYDTA
designated for transfer easy weight data (no more than LONG)

You can shared data among process use memory mapped files
or use __declspec(allocate) see MSDN or "Ritcher Programming for Windows"

Re: passing structures across processes

autodebug25-Mar-04 20:34

autodebug

25-Mar-04 20:34

You can't used class with WM_COPYDATA. Only like this.

typedef struct
{
char name[256];
char job[256];
} Raghu;

Raghu raghu;
strcpy(raghu.name, "Raghu");
strcpy(raghu.job, "none");

COPYDATASTRUCT datastruct;
datastruct.lpdata = (void*)&raghu;
datastrcut.cbdata=sizeof(raghu)?

::SendMessage(HWND_BROADCAST, WM_COPYDATA, (WPARAM)this->GetSafeHwnd(), (LPARAM)&datastruct);

---------------------------
Auto Debug for Windows
website: http://www.autodebug.com/

Re: passing structures across processes

Raghunandan S25-Mar-04 21:55

Raghunandan S

25-Mar-04 21:55

Hi,
Thanks for the suggestion.
The code works.but whenever i send this broad cast message microsoft outlook gives a message
"The command line argument is not valid. Verify the switch you are using.".
i tried giving different value to datastruct.dwData variable.but is of no use.can you please help me on this

Regards
Raghu

Re: passing structures across processes

wb26-Mar-04 0:33

26-Mar-04 0:33

if you broadcast a message, all the apps are geting it and if they have a function mapped to this message, you get funny results.

you mustnt broadcast a message. send it to a particular window.

GetDlgCtrlID returns zero

Mehran Ziadloo25-Mar-04 19:36

Mehran Ziadloo

25-Mar-04 19:36

Hi I have a problem with windows API in VC++ 6.0 and I hope someone helps me.
Consider two dialog boxes which use the same WndProc, all I want to do is to know which dialog has called the WndProc at a time.
To create a dialog box I use the "CreateDialog" API and I think my answer has something to do with "GetDlgCtrlID" function. But this function always returns zero!! So I'm stuck and don't know what to do..

Really appreciate any help
Mehran Ziadloo

overloading [] for a struct

monrobot1325-Mar-04 18:46

monrobot13

25-Mar-04 18:46

I have a structure like this:

typedef struct tagInputFields
{
	UINT	nMask;
	CString field1;
	CString field2;
	CString field3;
	CString field4;
	CString field5;
	CString field6;
}

what I'm wondering is if it's possible to overload the [] operator to offset into the structure. If so I would appreciate an example of how I might do it as I'm lost. So for example if I put

// m_ifFields is a tagInputFields structure
m_ifFields[1] // it would return field1

Thanks.

- Aaron

Re: overloading [] for a struct

Taka Muraoka25-Mar-04 18:58

Taka Muraoka

25-Mar-04 18:58

This would be a really bad idea since it would be totally confusing to anyone reading your code!

Why don't you do it like this:

typedef struct tagInputfields
{
    UINT nMask ; 
    CString fields[5] ; 
} ;

CString val = m_ifFields.fields[1] ;

Lets be honest, isn't it amazing how many truly stupid people you meet during the course of the day. Carry around a pad and pencil, you'll have twenty or thirty names by the end of the day - George Carlin

Awasu 2.0 [^]: A free RSS reader with support for Code Project.

Re: overloading [] for a struct

Prakash Nadar25-Mar-04 19:15

Prakash Nadar

25-Mar-04 19:15

I dont know wheather [] operator can be overloaded in struture, but you can always use class and over load it, it wont make any change in the usage.

MSN Messenger.
prakashnadar@msn.com

Tip of the day of visual C++ IDE.
"We use it before you do! Visual C++ was developed using Visual C++"

Re: overloading [] for a struct

Maxwell Chen25-Mar-04 19:27

Maxwell Chen

25-Mar-04 19:27

Hi Prakash, in C++, a struct is the same as a class except that all the members of a struct are public by default.

class AA
{
  // private by default.
public:
  AA() { }
};

struct BB
{
  // public by default.
  BB() { }
};

Maxwell Chen

Re: overloading [] for a struct

Michael Dunn25-Mar-04 19:29

Michael Dunn

25-Mar-04 19:29

First you have to decide whether you want the result of operator[] to be an lvalue (meaning, you can assign to the result). Let's assume no for the time being. It's customary to have two versions, one for const this and one for non-const this to maintain the best const-correctness. It would go like:

CString tagInputFields::operator[](int idx)
{
  switch ( idx )
  {
    case 1: return field1; break;
    case 2: return field2; break;
    // and so on...
    default: /* some kind of error handling here */
      return _T("");  // fall back case, empty string
  }
}
 
const CString tagInputFields::operator[](int idx) const
{
  switch ( idx )
  {
    case 1: return field1; break;
    case 2: return field2; break;
    // and so on...
    default: /* some kind of error handling here */
      return _T("");  // fall back case, empty string
  }
}

Yes, the two are identical except for the function prototype. That is, again, pretty normal since you are returning the same thing in each case, it's the prototype that makes the data const or not.

--Mike--
Personal stuff:: Ericahist | Homepage
Shareware stuff:: 1ClickPicGrabber | RightClick-Encrypt
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----
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-- Paul Watson, Linux Zombie

Re: overloading [] for a struct

monrobot1325-Mar-04 21:07

monrobot13

25-Mar-04 21:07

Thanks for the help Mike, I'll give that a try and see how it works out.

Thanks again.

- Aaron

Running Application

Anonymous25-Mar-04 17:04

Anonymous

25-Mar-04 17:04

How can i know name of the currently running application in win 2000? Where they are stored ,is it they are in windows registry? give me some api.

Re: Running Application

Monty²25-Mar-04 19:45

Monty²

25-Mar-04 19:45

maybe this[^] will help

C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do, it blows away your whole leg

Re: Running Application

Dimitris Vasiliadis24-May-04 12:55

Dimitris Vasiliadis

24-May-04 12:55

Check GetModuleFileName in MSDN

...Plug & Pray... Dead | X|

Cryptography in VC++ 6

kempyeng25-Mar-04 16:39

kempyeng

25-Mar-04 16:39

Hi all,
I try to make simple program (from msdn sample) to encrypt data using Visual C++ 6, this is the program :

#include <wincrypt.h> // CryptoAPI definitions

#define MS_DEF_PROV "Microsoft Base Cryptographic Provider v1.0"
#define PROV_RSA_FULL 1

BOOL bResult;
HCRYPTPROC hProv;

// Attempt to acquire a handle to the default key container.
bResult = CryptAcquireContext(
&hProv, // Variable to hold returned handle.
NULL, // Use default key container.
MS_DEF_PROV, // Use default CSP.
PROV_RSA_FULL, // Type of provider to acquire.
0); // No special action.

// Release handle to container.
CryptReleaseContext(hProv);

but when I compile those codes, I get error messages like this :

error C2065: 'HCRYPTPROC' : undeclared identifier
error C2146: syntax error : missing ';' before identifier 'hProv'
error C2065: 'hProv' : undeclared identifier
error C2065: 'CryptAcquireContext' : undeclared identifier
error C2065: 'CryptReleaseContext' : undeclared identifier

I don't understand, these codes is very simple and I capture these codes from MSDN (so it must be success). Can anyone help me ?
Thanks

Re: Cryptography in VC++ 6

markgr25-Mar-04 19:24

markgr

25-Mar-04 19:24

I know this sounds like a stupid question but you have included 'WinCrypt.h' haven't you?

I have not tried the code myself but normally this would be the first thing I would check.

You might also need to link against Advapi32.lib as well.

If I get chance then I will try and build the MSDN code and see why it does not work - but it looks like it's just the TYPSDEF's that it can't find - so try and include the header file and hopefully that should sort it out

Mark.

Re: Cryptography in VC++ 6

22491725-Mar-04 20:11

224917

25-Mar-04 20:11

add following line b4 including "wincrypt.h" Smile | :)

#define _WIN32_WINNT 0x0400

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