C / C++ / MFC

Re: byte alignment issue? Writing struct to file in binary mode.

7-Sep-09 4:57

I have also run it on my (Windows 7, 32 bit) system and results are as expected. The default value for char is ASCII on this system so maybe there is something in your project settings that is forcing it to Unicode.

Luc Pattyn7-Sep-09 2:39

Luc Pattyn

7-Sep-09 2:39

Hi,

if you can modify the struct any way you want, I suggest you reorder its content from largest to smallest item, that way no padding will be applied, hence no padding instructions will be necessary.

Like so:

unsigned int i1;
unsigned int i2;
unsigned short s1;
unsigned short s2;
char c[2];

If that is not possible, you must make sure all parties involved use the same padding rules.

Smile | :)

Luc Pattyn

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modified on Monday, September 7, 2009 12:10 PM

Re: byte alignment issue? Writing struct to file in binary mode. [modified]

Sauce!7-Sep-09 6:04

Sauce!

7-Sep-09 6:04

Unfortunately I can't change the order of the struct's members because I'm trying to write the header for a bmp file. Is there anything else I can do?

edit: packing works fine now :S strange.

modified on Monday, September 7, 2009 12:10 PM

Re: byte alignment issue? Writing struct to file in binary mode.

Luc Pattyn7-Sep-09 6:16

Luc Pattyn

7-Sep-09 6:16

sure, one of three things:

1. explain to the compiler exactly what it is you need, using switches and/or pragma directives, as others already told you
2. write(or read) your struct with explicit code, one statement for each field, using the method/function that fits the type of the field
3. don't use a struct at all; use a byte array, and write into/read from it using methods that deal with individual bytes and perform the necessary conversion from/to multi-byte data types, such as
int x=(((array[y+3]<<8)|array[y+2])<<8)|array[y+1])<<8)|array[y+0];
BTW: if you don't like/trust such code, you can also use a local union of a small byte array and the type of interest.

Smile | :)

Luc Pattyn

Have a look at my entry for the lean-and-mean competition; please provide comments, feedback, discussion, and don’t forget to vote for it! Thank you.

Re: byte alignment issue? Writing struct to file in binary mode.

Richard MacCutchan7-Sep-09 10:59

7-Sep-09 10:59

Take look at this.

Strings in EXE

choramale_vs7-Sep-09 1:45

7-Sep-09 1:45

If I have strings(variables) in my application, does these strings present in the string table of exe?

Richard MacCutchan7-Sep-09 1:52

7-Sep-09 1:52

A string constant in your inline code (e.g. printf("A string");) is compiled into the data portion of the object file. Such a string can be found in the exe by reading the entire file and looking for 'printable' characters. However only strings that are declared in resource string tables can be found using the FindResource() function.

choramale_vs7-Sep-09 2:26

7-Sep-09 2:26

I have to display all the strings present in an EXE file (i.e. compiled CPP file present in debug folder). How do i do this? I have written the following code. Can u please tell me what the problem is?.

#include "stdafx.h"
#include "windows.h"
#include "tchar.h"
#include "stdio.h"
#include "string.h"

BOOL CALLBACK MyStringCB(HMODULE some_library,LPCTSTR RT_String,LPTSTR buffer,LONG_PTR aux_param);

char buffer[200];

int _tmain(int argc, _TCHAR* argv[])
{DWORD S;
 LPCTSTR RT_String=NULL;
LONG_PTR aux_param=NULL;
	BOOL q,r;
	HMODULE some_library = LoadLibrary("C:/Hi/Debug/Hi.exe");
	q=  MyStringCB(some_library,RT_String,buffer,aux_param);
r=EnumResourceNames(some_library, RT_STRING, MyStringCB, aux_param);

S=GetLastError();

return 0;

}

BOOL CALLBACK MyStringCB(HMODULE some_library,LPCTSTR RT_String,LPTSTR buffer,LONG_PTR aux_param)
 {  DWORD startId = ((DWORD)buffer - 1) * 16; 
 DWORD i, endId = startId + 16;
   for (i = startId ; i < endId; ++i) 
 {    LoadString(some_library, i,buffer,sizeof(buffer)); 
 } 
 return TRUE;
 }

Richard MacCutchan7-Sep-09 2:30

7-Sep-09 2:30

choramale_vs wrote:
LoadString(some_library, i,buffer,sizeof(buffer));

You are loading the string but you do not diplay it anywhere...

choramale_vs7-Sep-09 2:51

7-Sep-09 2:51

After displaying buffer value am getting a Blank Screen

Richard MacCutchan7-Sep-09 4:21

7-Sep-09 4:21

Sorry, but this really does not explain your problem. From some of your other questions and answers I suggest you may need to study this item on Resources.

CPallini7-Sep-09 1:55

CPallini

7-Sep-09 1:55

Literals are NOT stored in the string table, if I guessed what are you asking... Roll eyes | :rolleyes:

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

choramale_vs7-Sep-09 3:50

7-Sep-09 3:50

I have printed "Hi" in my application.
If I want to retrieve "Hi" from an EXE.
What should I do?

Michael Schubert7-Sep-09 4:03

Michael Schubert

7-Sep-09 4:03

Put your strings into a stringtable.

choramale_vs7-Sep-09 4:14

7-Sep-09 4:14

That's what how to put it into string table and then how to display it from EXE?

Michael Schubert7-Sep-09 4:37

Michael Schubert

7-Sep-09 4:37

Create a resource file (.rc) and add your string(s) to the stringtable. Then you can simply load the strings with LoadString() or CString::LoadString() if you are using MFC.

Nick_1117-Sep-09 6:17

Nick_111

7-Sep-09 6:17

Isn't there a string table which is automatically made?
How to retrieve from that string table?

TrackPopupMenuEx not popup menu on rite cordinates in ListCtrl.

Michael Schubert7-Sep-09 6:54

Michael Schubert

7-Sep-09 6:54

Are you the same person as the thread starter? Or do you just have the exact same problem?

Anyway, it very much depends on how you created your application. If you used a Visual Studio wizard then you will possibly already have a resource script included in your project, depending on which app type you chose.

If not - and you are using Visual Studio - it's very simple to add resources to your project. Look at the documentation.

MySQL connection

rdop7-Sep-09 1:16

rdop

7-Sep-09 1:16

Hi
How to established connection in mysql without ODBC?
Plz help me

Le@rner7-Sep-09 1:07

Le@rner

7-Sep-09 1:07

Hi all,

i want to use Menu on right click of ListCtrl,

i m using this code

void CTest::OnNMRClickList(NMHDR *pNMHDR, LRESULT *pResult)
{
	LPNMITEMACTIVATE pia = (LPNMITEMACTIVATE)pNMHDR;

	UINT flags; 
    DWORD pos = GetMessagePos(); 
	
	CPoint point(LOWORD(pos), HIWORD(pos));

    m_List.ScreenToClient(&point); 
    int nItem = m_List.HitTest(point, &flags);

	
	HMENU hMenu = ::CreatePopupMenu();
	if (NULL != hMenu)
	{
		// add a few test items
		::AppendMenu(hMenu, MF_STRING,   1, "Test1");
		::AppendMenu(hMenu, MF_SEPARATOR,2,	"");
		::AppendMenu(hMenu, MF_STRING,   3, "Test2");
		::AppendMenu(hMenu, MF_SEPARATOR,4,	"");
		::AppendMenu(hMenu, MF_STRING,   5, "Test3");
		ClientToScreen(&point);

		int sel = ::TrackPopupMenuEx(hMenu,TPM_LEFTALIGN|TPM_RETURNCMD,point.x,point.y,m_hWnd,NULL);

		switch(sel)
		{
		case 1:
			{
				//do sumthing
			}
			break;

		case 3:
			{
				//do sumthing
			}
			break;

		case 5:
			{
				//do sumthing
			}

			break;
		
		}
	}

	*pResult = 0;
}
//-------------------------------------------------------------------------------------------------------------

its working fine only one problem is here its not popup the menu on tip of mouse cursor.

please tell me where i m wrong.

please help me .

thanks in advance.

To accomplish great things, we must not only act, but also dream;
not only plan, but also believe.

Re: TrackPopupMenuEx not popup menu on rite cordinates in ListCtrl.

Richard MacCutchan7-Sep-09 2:20

Re: TrackPopupMenuEx not popup menu on rite cordinates in ListCtrl.

7-Sep-09 2:20

"_$h@nky_" wrote:
DWORD pos = GetMessagePos();

CPoint point(LOWORD(pos), HIWORD(pos));

m_List.ScreenToClient(&point);

I think perhaps this is where your problem lies. The list box returns the cursor position in the LPNMITEMACTIVATE structure. You will need to convert this position to its absolute screenvalues via
ClientToScreen(hWnd, &pia->ptAction);
and then use pia->ptAction.x and pia->ptAction.y in your call to TrackPopupMenuEx().

Le@rner7-Sep-09 2:49

Le@rner

7-Sep-09 2:49

No its not working

To accomplish great things, we must not only act, but also dream;
not only plan, but also believe.

Re: TrackPopupMenuEx not popup menu on rite cordinates in ListCtrl.

Richard MacCutchan7-Sep-09 4:16