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It's a two-step process:
- First, You must know what is the data format of your raw image.
- Then, you have to actually create the Windows Bitmap.
If you have a look at the source code of my "Plain C resampling DLL" [^] then you may have a clue on how the second step is performed.
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]
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This is related error to a C std function strtoul.
This problem started coming up when I migrated from VS 2003 to VS 2008.
While building c code I am getting the following error:
############################################################################
libcmtd.lib(strtol.obj) : error LNK2005: strtoul already defined in test.lib(string.obj)
c:\xyz.exe : fatal error LNK1169: one or more multiply defined symbols found
*** Error code 1169
clearmake: Error: Build script failed for
"c:\xyz.exe "
############################################################################
This error tells us that while building the libcmtd.lib it got the definition of the strtoul function in the test.lib
The std strtoul function is defined in the file strtol.c which is a standard file like stdio.h.
I have also customized definition of this function defined in my project.
While building the code my project references the customized code and not the std function
I want to use the standard strtoul function.
The customized strtoul is not be removed completey as some files need to reference the customized strtoul while some part will refer the original strtoul.
Any solution for it ?
Why is the VS2008 linker using the customized function instead of using the standard one.
What the difference between VS2003 and VS2008 which is causing the error.
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Why don't you just change your function name (e.g. from strtoul to custom_strtoul)?
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]
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Thanks Pallini for the reply.
I cannot change the function name as it it is referenced at many places
. If I change the name then all these places will have to be changed which is not desired.
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rupeshk_p wrote: If I change the name then all these places will have to be changed which is not desired.
Why?
You may also use an old-dirty-trick on such files:
#define strtoul customized_strtoul
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]
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rupeshk_p wrote: I have also customized definition of this function defined in my project.
Why re-use the name of a function defined in the standard? That seems the foolish thing to me - if you'd just used a different name, than a) you'd not have these linker problems, and b) you'd be able to see exactly where you used the 'customised' function.
rupeshk_p wrote: Why is the VS2008 linker using the customized function instead of using the standard one.
Probably because the linker sees your definition is test.lib(string.obj) before it sees the one in libcmtd.lib.
rupeshk_p wrote: What the difference between VS2003 and VS2008 which is causing the error.
The behaviour actually changes between VS2003 and VS2005 (yes, I've tried it, with VS2003, 2005 and 2008) - VS2008 just follows VS2005's behaviour. The only thing I can think of is that the C run-time now requires strtol, and so will bring in strtol.obj (which contains both strtol and strtoul). [later] This would appear to be confirmed - when I compile and link this small program (which I've called a.c):
#include <stdio.h>
int main()
{
printf("%d\n", 1);
}with the command cl a.c /link /map, the map file contains strtol when built with VS2008, but doesn't when built with VS2003.
rupeshk_p wrote: Any solution for it ?
Add implementations of all the functions exported by strtol.obj from libcmtd.lib?
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Thanks Stuart for the details
The same name of the customized function is as per deisgn
I cannot use a different name for the customized function
You are correct that the linker sees the definition is test.libfirst and then in libcmtd.lib which causes the error.
From the sample code you have shown it imples that the vs2008 build includes the standard strtoul while the vs2003 does not
Am I correct ?
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Yes. As I said - the runtime (that bit that you have to have) must have changed to link it in
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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Can you let me know what does the terms _Check_return_ and _CRTIMP means
in the definition below
_Check_return_ _CRTIMP unsigned long __cdecl strtoul(_In_z_ const char * _Str, _Out_opt_ _Deref_post_z_ char ** _EndPtr, _In_ int _Radix);
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I'll do better than that - I'll show you how to find them yourself:
- Right-click on the thing you want to find the definition of and select "Go To Definition"
- There is no step 2
[edit] However, most of those macros actually resolve to nothing when you're compiling normally - the _Check_return, _In_z_, _Out_opt_, _Deref_post_z_ and _In_ macros only have a definition if you're using the PreFast static analysis tool. [/edit]
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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Digging further into stdlib.h of VS2003 saw
#ifndef _CRTIMP
#ifdef CRTDLL
#define _CRTIMP __declspec(dllexport)
#else /* CRTDLL */
#ifdef _DLL
#define _CRTIMP __declspec(dllimport)
#else /* _DLL */
#define _CRTIMP
#endif /* _DLL */
#endif /* CRTDLL */
#endif /* _CRTIMP */
So _CRTIMP is a #define which tells whether the function is exported from or imported to the C library.
_Check_return_
Return value must not be ignored by callers of this function.
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rupeshk_p wrote: So _CRTIMP is a #define which tells whether the function is exported from or imported to the C library.
Spot on
rupeshk_p wrote: _Check_return_
Return value must not be ignored by callers of this function.
That's right - but as I said, it's only used by Microsoft's static analysis tool - the compiler sees nothing for that
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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On building the SAME CODE for both VS2003 and VS2008 I found the following
1) For VS2003 during the build the linker outputs as
Searching c:\...\test.lib
.
.
.
Searching C:\MSSDK\Lib\amd64\libcmtd.lib:
No error comes up and build succeeds.
2) For VS2008 the linker outputs as
Searching c:\...\test.lib
.
.
.
Searching C:\\Program Files\\Microsoft Visual Studio 9.0\VC\lib\amd64\libcmtd.lib:
libcmtd.lib(strtol.obj) : error LNK2005: strtoul already defined in test.lib(string.obj)
So we see that the libcmtd.lib gets linked after test.lib in both cases.
The libcmtd.lib of both VS2003 and VS2008 has the definitions of strtoul.
But the build fails in VS2008.
Does /MT or /Mtd option of linking has anything to do with this error?
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rupeshk_p wrote: The libcmtd.lib of both VS2003 and VS2008 has the definitions of strtoul.
But the build fails in VS2008.
That is because the VS2008 build pulls in strtol.obj out of libcmtd.lib (that's what libcmtd.lib(strtol.obj) means), whereas the VS2003 build doesn't.
Object code libraries aren't really single units - they're a bit like zip files, in that they're made up of lots of different files internally. What this means is that if nothing requires a symbol that is only found in libcmtd.lib(strtol.obj), libcmtd.lib(strtol.obj) will not be looked at by the linker. This is what happens with the VS2003 build.
The VS2008 build, however, needs a definition of _strtol - that must have been added to the C run-time somewhere. Now, _strtol is only found in libcmtd.lib(strtol.obj). So, the linker adds the object file libcmtd.lib(strtol.obj) to the build. However, when it then comes to tie all the object files together, it finds two definitions of _strtoul - the one in libcmtd.lib(strtol.obj) and the one in your code. It does not (cannot) know which to use, so it raises a fatal error.
rupeshk_p wrote: Does /MT or /Mtd option of linking has anything to do with this error?
I doubt it, but you could try.
What you have encountered however, is the reason that you shouldn't do things like redefine standard functions - some completely unrelated change in the Microsoft libraries has broken your build!
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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One question Stuart.
How to find in detail( similar to the explanation you gave about the VS2003 and VS2008 difference ) about the functioning of VS 2008 or previous versions in depth.
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Hello . I am a beginner in craft , but I like this class CCrypto , used in one of my project , to crypt a pass string into registry ,where goes perfectly and now I want to use in a MDI arhitecture , to encrypt a CRichEditCntrItem class , but I don't know how to do that .... can you help me ? Because I made a Serialize method in CMyCntrItem , and here I try to acces Encrypt method of CCrypt , but this method call again Serialize method of CMyCntrItem .... and looping never end ...
here is code sample :
void CMyCntrItem::Serialize(CArchive &ar)
{
if(ar.IsStoring())
{
CCrypt crypt;
CByteArray arrBytes;
crypt.DeriveKey("123456");
if(crypt.Encrypt(*this,arrBytes) == true) /// and here begin to loop forever ...
ar << arrBytes;
}
else
{
/// Loading code ... ?!
}
}
If you say , I will attach my all attempt project........
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mesajflaviu wrote: if(crypt.Encrypt(*this,arrBytes) == true) /// and here begin to loop forever ...
So, you're asking us to help you solve a bug in code that we've not only never seen, but the only person who has seen it is you? I know we're good here, but we're not *that* good. (Except Rajesh)
All I can think of is that you break this in to three steps:
1/ Work out how to get the rich edit controls data,
2/ Work out how to set the rich edit control,
3/ Put in your encryption code.
Iain.
In the process of moving to Sweden for love (awwww).
If you're in Scandinavia and want an MVP on the payroll (or happy with a remote worker), give me a job! http://cv.imcsoft.co.uk/[ ^]
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Firs of all , I want to say that I'm very sorry because I write so little about my problem ( my mistake !! ) , I should say more , so , in fact , it's about probably something simple :
I intend to use CCrypto from Dave Kerr , take from here :
A simple MFC class to encrypt data with the Crypto API[^]
and crypt a CRichEditCntrItem ....I don't know where put next code ( sampled by Dave ) :
// Now I want to encrypt my applications document object.
CDocument* pDoc = GetDocument();
if(crypto.Encrypt(*pDoc, arBytes) == true)
{
// Store the byte array in a file, the registry, whatever.
}
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OK, you still need to break your problem into bits.
It looks like the CCrypto object has an encrypt and decrypt function that call (I guess from your first post) the CMyDocument::Setialize method to put the data in / out of the document. Feel free to use your debugger to see if I'm telling the truth.
BUT,
A CRichEditCtrl is a UI item, and would either be part of a CRichEditView. You would have to add a handler to the view which would fire every time it changes (ie, ON_EN_UPDATE) and save the text from the rich edit control to a CString (or std::string, or whatever you like) in the document. Then you can archive that.
As for decryting, that article has a good example of that. After decrypting the text, it will be deserialized into your documents text string. Call CDocument::UpdateAllViews, and add code to CMyView::OnUpdate to put that text into the rich edit.
In a similar thought, if you're in an MDI enviroment, you might have multipler views pointing at one document. You'll need to keep that in sychronisation with each other.
I hope that gives you something to think about,
Iain.
In the process of moving to Sweden for love (awwww).
If you're in Scandinavia and want an MVP on the payroll (or happy with a remote worker), give me a job! http://cv.imcsoft.co.uk/[ ^]
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Thank you for your answers , I will try what you said and let you know if I make it !
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Hy.I hope to follow this track , because I try to solve my problem in the way that you said , but CRichEditCntrItem item could be an other things than characters ( a .jpg item for sample ) so how to save that in a CString ? And to be sure that I understand how to solve problem : I create a CMyView CString member variable , to save characters item on CMyView::OnUpdate handler , and from here archive that in CMyDocument class ? I understand well ?
modified on Monday, May 4, 2009 6:51 AM
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Hi,
i am looking for a function/class which allows to load a region of a JPG/PNG file ... so i need a function like:
LoadImageRegionFromFile(LPCTSTR lpFilename,int x,int y,int width,int height)
to extract a image rectangle with <width> and <height> dimension from the file <lpfilename> at the point (x/y) ... it's not important for me if i get the result as a new file or as a byte array ...
More important: portable code (so pure C/C++ is welcome)
I searched here in CP but found nothing ...  ... has anybody a hint for me?
Thanx!
Frank
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Probably you should:
- load the image from file.
- Get the proper region data.
- Write a new image file with region data.
For step (1),(3) you need a JPEG portable library.
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]
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