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this 2 block will delimit every 1-Byte-aligned structs/classes/unions between the pack and the pop.
the subtlty is in the syntax understood by the compiler.
#if defined( _MSC_VER ) && _MSC_VER > 600 searches if the version of the compiler is higher that Visual C++ 6. if so, it tells to the compiler to user the 1 byte alignment with #pragma pack( push, 1 ). but it the compiler is more recent #pragma pack( 1 ) is sufficient. Same applies to the #pragma pop syntax.
you have to know that the compiler manages such alignments with a stack of integers. the current alignement is the integer at the top of the stack. but at any time, you can add a new value (push), or remove some (pop)...
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Hi toxcct,
First of all... Thanks for your answer.
But the problem was not with the version of compiler.
The things that I didn't understand are the pragma pack (...), the WIN32_LEAN_AND_MEAN and the __cdecl
Anyways thanks.
Greetings.
--------
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
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as explained in the MSDN, "When WIN32_LEAN_AND_MEAN is defined, a large number of header files are deliberately excluded by windows.h". read here[^] for a short brief.
for the __cdecl, this is what we name a "calling convention".
a calling convention is for the compiler to which of the caller or the callee is to clean the call stack.
I explain myself. when you call a function, a call stack is implicitely created to push the parameters and some extra informations such as the execution pointer. but once the function called ended its process, the memory then allocated has to be freed. such a memory can me cleaned by either the caller or the callee, but the important point here is that BOTH must accort themselves to use the same convention (imagine the leak if none is freeing the memory, or the disaster if both are cleaning a one and only memory place).
that is, several calling convention exist such like __cdecl, __stdcall, __fastcall, __thiscall...
google/MSDN can help you more than me for sure.
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I already was tin MSDN and didn't understand it well. With your explanation I can now imagine some things. I will make my own try-errors to check if I have got it. Thanks
Greetings.
--------
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
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Are you not understanding stacks (e.g., pushing and popping), or byte alignments?
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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Also...
In a simple mode with a comparison: The stack is a box with two doors, where the allocation of the memory are packets incoming through the "push" side, then the cpu use the info that is inside (like toxcct said, the pointer to an application that is running to have access or communication). Once the information is not needed anymore, then the box is discharged through the "pop" side to let the box containing new usefull things. If the box is overloaded, an error comes and the things doesn't work fine anymore.
about the bytes alignment... Maybe is a problem of language, but I can not relate the term with anything logical.
For me is like:
----Byte----
----Byte---- They are aligned
-Byte-------
------Byte-- They are not aligned
Greetings.
--------
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
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Using your analogy, a stack would only have one door, whereas a queue would have two doors. A stack gets items pushed and popped from the same end. A queue gets items pushed onto one end and popped from the other end.
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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Ahmm, ok
then it can happen like in the step7. If one programmer opens/calls a lot of different functions/processes, without closing the previous ones... there must be a moment where the stack overflows and then the programm/cpu crashes.
What about the bytes alignment? Was I right?
What I still don't understand (sorry if I ask a lot) is what a relation has the alignment of the Bytes with the question of the stack.
If the Bytes of a stack are pushed and popped through the same entry... with what should to be aligned?
Greetings.
--------
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
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You seem to be confusing structure alignment (the byte packing stuff) with stack operations.
The #pragma pack(n) preprocessor directive specifies packing alignment for structure and union members. For example, for n having a value of 1, 2, 4, 8, or 16, each structure member after the first is stored on the smaller member type or n-byte boundaries.
Each occurrence of #pragma pack (push) stores the current packing alignment on an internal compiler stack. Each occurrence of #pragma pack (pop) retrieves the value at the top of an internal compiler stack and makes that value the new packing alignment.
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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Yes I was mixing concepts.
Thanks, I don't understand it perfect, but more than before. This is in a level higher than mine. But at least I can now read the info without thinking is written in japanese :P
Thank you both
Greetings.
--------
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
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I have created a custom control which contains two buttons. I want these buttons to display the same arraows which are displayed on a scrollbars buttons. So, I create a font using the Marlett face name and instruct the button to use this font via WM_SETFONT. I also set the buttons text to "3" 4, 5 or 6 ( which maps to the arrows ). But the button still displays the number instead of the arrow. The marlett font doesn't contain any ASCII characters, it's all pictographs!
I have verified that the button is using the font via WM_GETFONT. Everything appears to be correct except that the arrows are not being displayed. Any clue as to what's gone wrong?
HFONT hFont = NULL;
hFont = (HFONT)SendMessage( m_hButtonUp, WM_GETFONT, 0, 0 );
if ( ! hFont )
hFont = (HFONT)GetStockObject( DEFAULT_GUI_FONT );
if ( ! hFont )
hFont = (HFONT)GetStockObject( ANSI_VAR_FONT );
if ( hFont )
{
LOGFONT lf;
GetObject( hFont, sizeof( LOGFONT ), &lf );
_tcscpy_s( lf.lfFaceName, LF_FACESIZE, _T("Marlett") );
hFont = CreateFontIndirect( &lf );
SendMessage( m_hButtonUp, WM_SETFONT, (WPARAM)hFont, TRUE );
SendMessage( m_hButtonDown, WM_SETFONT, (WPARAM)hFont, TRUE );
SendMessage( m_hButtonUp, WM_SETTEXT, 0, (LPARAM)_T("3") );
SendMessage( m_hButtonDown, WM_SETTEXT, 0, (LPARAM)_T("4") );
}
Waldermort
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The returncodes of the SendMessage() and try an Invalidate() of the controls 
Greetings from Germany
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SendMessage( m_hButtonUp, WM_SETFONT, (WPARAM)hFont, TRUE );
Have you checked the return value ? I mean has the font got set ? If not, check using different fonts like arial etc.
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The WM_SETFONT does not return a value according to MSDN, also I noted in my post that I did verify that the font has been set.
The mistake was simple, I forgot to set the SYMBOL_CHARSET flag.
Thanks anyway.
Waldermort
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Hello Friends,
I am using the Win32 Application. In this project I am using EM_GETSELTEXT to get the selected Text From Rich Edit Control.
RichEdit Control is in another window. I have retrived its handle through FindWindowEx() Function.
But When I use the Following code it doesn't retrive the selected text
WCHAR SText[100]={};
lr = SendMessage(hChild,EM_GETSELTEXT ,(WPARAM)0,(LPARAM)SText);
if(lr <0)
{
dError = GetLastError();
}
lr shows the Number of charcter selected. But the SText(STEXT="") is empty after SendMessage.
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Gaurang, I completely agree with you. It returns the length but not the value.
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But why ??? do u have any Idea. ?? or is there any other way I can got the Selected text. WM_GETTEXT and WM_SETTEXT working fine.
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GauranG033But When I use the Following code it doesn't retrive the selected text
It fails as a result of Unicode being used. You'll find that if you use ANSI, EM_GETSELTEXT would work as expected. Is that a viable option?
If not, use this:
char sz[100] = {'\0'};
LPWSTR SText;
LRESULT lr = SendMessage(hChild, EM_GETSELTEXT, 0, (LPARAM) sz);
USES_CONVERSION;
SText = A2W(sz);
Notice your text that I quoted above is not formatted correctly.
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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I tried you code. But still facing the same problem. Empty String.
is there any other way I can get the selected Text By user.
I have tried it in MFC application Like this
CWnd *hParent = FindWindow(_T("TfrmChat"),0);
CWnd *hChild = FindWindowEx(hParent->m_hWnd,0,_T("TPanel"),0);
hParent = FindWindowEx(hParent->m_hWnd,hChild->m_hWnd,_T("TPanel"),0);
hChild = FindWindowEx(hParent->m_hWnd,0,_T("TExRichEdit"),0);
char sz[100] = {'\0'};
LPWSTR SText;
LRESULT lr;
lr = hChild->SendMessage(EM_GETSELTEXT, 0, (LPARAM) sz);
USES_CONVERSION;
SText = A2W(sz);
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GauranG033Empty String.
How are you verifying this?
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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Hello, guyz.
In my current project I want to convert a tiff file(*.tif) to a bitmap file(*.bmp) but I don't know how to do it.
Do you have any idea on how will I able to do it or knew a thread or post with this topic?
Hope you can help me with this.
Thank you.
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An easy way is to select a CBitmap in a DC and draw the tiff. Or I know the CXImage class here at CP.
Greetings from Germany
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Thank you for your time KarstenK.
Can you please state more in details, because i'm just starting in C++.
Best regards
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Then you got to learn a lot and be patient "Rom wasnt build on a day".
Conversion of graphics is an interface problem: you need to transport the data from the source to a (temporary) format which the target format can understand.
I strongly advice you to download and step trough this really good project: http://www.codeproject.com/bitmap/cximage.asp[^]
If you really like graphic conversion you will agree that this one is outstanding:
http://www.codeproject.com/bitmap/extendedbitmap2.asp[^]
This will take you some hours, cups of coffee and some headaches if you are really engaged. But it is worth it.
Greetings from Germany
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Writing a robust TIFF file loader is a big project.
If you can use GDI+, it can save alot of work.
There's also the ATL CImage class, which uses GDI+ for loading and saving image files.
With CImage, you could do it in a few lines of code:
#include <atlimage.h>
...
CImage image;
image.Load(_T("C:\\TIFFFile.tif"));
image.Save(_T("C:\\BMPFile.bmp"), Gdiplus::ImageFormatBMP);Note that BMP files have a limited set of supported image formats. See
the documentation for the BITMAPINFOHEADER struct for details.
Mark
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://codeproject.freetls.fastly.net/script/Forums/Images/coffee.gif)
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