Re: export and import DLL's - C / C++ / MFC Discussion Boards

Re: Updating Different Areas of a Control

Michael Dunn26-Nov-01 15:24

Michael Dunn

26-Nov-01 15:24

Call CWnd::InvalidateRect() and pass it the RECT of the area that needs to be redrawn.
In your painting code, check the DC's invalid region (it's a CDC or API function, I can't remember the name ATM) and only repaint that region.

--Mike--
http://home.inreach.com/mdunn/
While I can't be correct on all matters, I can make the reassuring claim that where I am inaccurate, I am at least definitively inaccurate.
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problems with dll

Stanislav26-Nov-01 10:30

Stanislav

26-Nov-01 10:30

i have a big problem linking a dll.
i thing the functions in the dll are old and are declarated with
__export, and can match this in my prototypes because
VC++ 6 doesn't know what __import is Smile | :)

.

1. with lib i make from the dll lib file, which i build with
my project, still no errors
2. then in header files i try to write the prototypes
something like that
extern "C" MTELConnect(...);
the compiler says no, and i use the __declspec(dllimport) also.
it compiles successfully,
but when tries to link
i got the following mistake
error LNK2001: unresolved external symbol __imp__MTELConnect
somebody help me Big Grin | :-D

Re: problems with dll

Joaquín M López Muñoz26-Nov-01 12:25

Joaquín M López Muñoz

26-Nov-01 12:25

Well you have quite a problem here...
If I'm not wrong, yo're trying to use an old 16-bit DLL with your 32-bit VC++ compiler. Unfortunately, this cannot be done directly. 16- and 32-bit are separate worlds inhabiting different memory spaces and they simply cannot be freely mixed.
I strongly suggest that you consider the possibility of getting the source code of that 16-bit DLL and try to recompile it with your 32-bit compiler (some modifications will surely be required). This is by far the easiest solution, if you can afford it. If for some reason this is not an option, keep reading.
To enable a 32-bit executable to call functions of a 16-bit DLL, you need an intermediate DLL that is able to speak both languages and make the translations necessary between them. This is what Microsoft call a thunk. They provide a thunk compiler and instructions on how to build 32-to-16, 16-to-32 and bidirectional thunks (on NT platforms, 32-to-16 is alas forbidden). A couple of URLs to start reading:

I had to build one of these thunks in the past and it is no easy task, though not impossible either, and the docs are pretty explanatory. Good luck if you enter the thunk trail.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: problems with dll

Stanislav27-Nov-01 11:23

Stanislav

27-Nov-01 11:23

ups, sorry i was confused
the truth is that the dll was compiled with the _export clause,
but know when i get much involved in the things i saw
that when i generate an import .lib file
with lib.exe /def:mydll.dll
and then when i dumpbin /exports mydll.lib

i get this
Dump of file mydll1.lib

File Type: LIBRARY

Summary

C3 .debug$S
14 .idata$2
14 .idata$3
4 .idata$4
4 .idata$5
C .idata$6
that means there is no exports there, and that i can't properly use
lib.exe (btw when i make the .lib file it gives me an warning

mydll1.dll : warning LNK4017: MZР statement not supported for the target platform; ignored

btw because i'was in a hurry i manage to run the library with LoadLibrary
and GetProcAddress, but i still want to manage the other way Smile | :)

best Stanislav

Re: problems with dll

Brad Bruce27-Nov-01 12:02

Brad Bruce

27-Nov-01 12:02

Try adding the function to the EXPORTS section of your def file. BTW the compiler should generate the .LIB for you.

export and import DLL's

26-Nov-01 9:40

I wrote successfully regular DLL by MFC AppWizard. "MyDLL.DLL"
My DLL import himself another DLL. "OuterDLL.DLL"

When MyDLL imports the OuterDLL statically (with the LIB file)it is all right.
But if it performed by Dynamic Linking (with LoadLibrary), When I try activate that MyDLL from client program (exe)I gets the following message error:
============================================================
The value of ESP was not properly saved across a function call .
This is usually a result of calling a function declared with one calling convention with a function pointer declared with a different calling convention.
=============================================================
Is this say that it impossible use Dynamic linking in DLL ?

Re: export and import DLL's

Joaquín M López Muñoz26-Nov-01 9:58

Joaquín M López Muñoz

26-Nov-01 9:58

Is this say that it impossible use Dynamic linking in DLL ?

No, it is perfectly possible to have dynamic linking of functions defined inside a DLL. You just have to do as the warning suggests and fix the calling convention used by the function. To use the example of your previous post, instead of

DWORD Func1(DWORD,char*);

write

DWORD WINAPI Func1(DWORD,char*);

and now define SQRTPROC as

typedef DWORD WINAPI (SQRTPROC) (DWORD,char*);

Hope this helps.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: export and import DLL's

mimi26-Nov-01 10:27

mimi

26-Nov-01 10:27

I tried it as following:

=============================================
HINSTANCE hInstance;
VERIFY (hInstance = ::LoadLibrary("c:\\windows\\system\\OuterDLL.dll"));

typedef DWORD WINAPI (SQRTPROC) (DWORD,char*); //Line 86
SQRTPROC* pFunc;
VERIFY (pFunc = (SQRTPROC*) ::GetProcAddress(hInstance, "MyFunc"));
==============================================
And I got in compilation the following errors :

MyDLL.cpp(86) : error C2059: syntax error : '('
(87) : error C2065: 'SQRTPROC' : undeclared identifier
(87) : error C2065: 'pFunc' : undeclared identifier
etc...

Re: export and import DLL's

Joaquín M López Muñoz26-Nov-01 11:33

Joaquín M López Muñoz

26-Nov-01 11:33

err... try this:

typedef DWORD (WINAPI * LPSQRTPROC) (DWORD,char*);
LPSQRTPROC pFunc;
VERIFY (pFunc = (LPSQRTPROC) ::GetProcAddress(hInstance, "MyFunc"));

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

left over IDC_ values in resource.h

Jason Hihn26-Nov-01 7:54

Jason Hihn

26-Nov-01 7:54

I have a dialog that's undergone heavy modifications, and I'm left with a ton of extra IDC_ values for controls that no longer exist.

Is there any utility or way to have it remove the unused control values?

I've also been expericing "duplicate control IDs" when renaming some. The bugger is that there are no duplicates. There were, but those were renamed or deleted, but it thinks they are stil there.

Thanks in advance

Re: left over IDC_ values in resource.h

Michael Dunn26-Nov-01 9:35

Michael Dunn

26-Nov-01 9:35

Go to View->Resource symbols. The ones in use will have a check mark, so you can delete the ones w/o checks.

--Mike--
http://home.inreach.com/mdunn/
While I can't be correct on all matters, I can make the reassuring claim that where I am inaccurate, I am at least definitively inaccurate.
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Re: left over IDC_ values in resource.h

Sidney Chong26-Nov-01 15:20

Sidney Chong

26-Nov-01 15:20

You might want to try this handy addin by Andy Metcalfe:

http://www.codeproject.com/macro/resorg.asp

It may help to solve your resource id woes. Smile | :)

Cheers

Anti-alias font in WebBrowser control

26-Nov-01 7:39

Hi All,

I've got a big problem and could somebody kindly give me a hand?

The requirement is to use WebBrowser control and display content in Anti-alias font. Assume 'smooth edges of screen fonts' display property is not checked. (we can't assume it is checked) How I can make the content of WebBrowser control render in Anti-alias font?

I've got some ideas but most of them are proven to be not working. Now, I'm thinking of solutions like creating a 'HFont' with 'CreateFont' that takes a 'ANTIALIASED_QUALITY' 'fdwQuality' parameter. And put the HFont to system by 'AddFontMemResourceEx' function. And let the HTML to specify using the new font. Do you think this method can work? any other good suggestions?

Thx and regards,
Confused | :confused:

mingfai

Reference:
AddFontMemResourceEx: adds the font resource from a memory image to the system.
http://msdn.microsoft.com/library/en-us/gdi/fontext_23zs.asp

common var for C and C++

meirav26-Nov-01 6:57

meirav

26-Nov-01 6:57

I have 2 fils in a project :
1 Cpp file and the second C file .
a variable x is declared in the Cpp file and i need that
the C file will "know" that variable.
is there supose to be a problem?
when i tried this:

Cpp File C_File

int x; extern int x
i get an error : unresolved external
I will be very glad to get any help
OMG | :OMG:

Re: common var for C and C++

Joaquín M López Muñoz26-Nov-01 7:09

Joaquín M López Muñoz

26-Nov-01 7:09

Put this in your .h:

#ifdef __cplusplus
extern "C" {
#endif
extern int x;
#ifdef __cplusplus
}
#endif

and this in your .cpp:

#include <···.h>
int x;

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: common var for C and C++

Nish Nishant26-Nov-01 7:11

Nish Nishant

26-Nov-01 7:11

meirav wrote:
int x; extern int x

hmmmm...
dont put both in the same file.

file1.cpp -> declare it there :- int x;
file2.c -> extern "C" int x;

Try that.
Nish

Sonork ID 100.9786 voidmain
www.busterboy.org
Nish is a BIG fan of Goran Ivanisevic

Radio Box

mvworld26-Nov-01 5:51

mvworld

26-Nov-01 5:51

If I have 2 radio boxes and I want to make sure the user can check only one of them at a time (ie if the user checks one, the other gets automatically unchecked).....then how do I do this?

Thanks.

Re: Radio Box

Nish Nishant26-Nov-01 6:33

Nish Nishant

26-Nov-01 6:33

lets say you have two pairs of 3 radio buttons [thus 6 total].
use the WS_GROUP style for the 1st and 4th.
Now you have two sets of 3-mutually exclusive radio buttons

Nish

Sonork ID 100.9786 voidmain
www.busterboy.org
Nish is a BIG fan of Goran Ivanisevic

Re: Radio Box

26-Nov-01 6:39

If you mean radio buttons, then have them on a group box.

Re: Radio Box

26-Nov-01 7:32

It seems if you place your group boxes with radio buttons in another group box, you can check only one button at a time effectively checking one group at a time. It needs a SetCheck() on the first button you want to start with.

Re: Radio Box

Michael Dunn26-Nov-01 9:40

Michael Dunn

26-Nov-01 9:40

The "group" attribute controls which radio buttons are linked up. It has nothing to do with being in a group box like the previous posts have said. The first radio button must have the group attribute set, the others must not have it set, then the control right after the last radio button in the tab order should have it set to mark the end of the group.

--Mike--
http://home.inreach.com/mdunn/
While I can't be correct on all matters, I can make the reassuring claim that where I am inaccurate, I am at least definitively inaccurate.
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MSXML & VC++ Book

Derek Price26-Nov-01 4:40

Derek Price

26-Nov-01 4:40

Hello,

I am interested in using the MSXML parser using VC++. It seems there are endless books on the subject for VB and every other language, but I haven't been able to find one for VC++ specifically. I know many code sites (MSDN, CodeProject, etc.) have articles, but I would prefer a book. Can anyone suggest a book that focuses on the MSXML parser and VC++ (not .NET)?

Thanks!
Derek

Re: MSXML & VC++ Book

Nish Nishant26-Nov-01 6:47

Nish Nishant

26-Nov-01 6:47

Hi Derek

You are correct there. Nearly all the documentation on MSXML is about VB. I had this same problem an year ago.

I finally ended up using Expat - an XML parser library in C

I believe that since then there is Expat++ which is a C++ class library

I'd recommend Expat unless you very specifically want to use MSXML

Regards
Nish

Sonork ID 100.9786 voidmain
www.busterboy.org
Nish is a BIG fan of Goran Ivanisevic

Re: MSXML & VC++ Book

Bill Wilson26-Nov-01 7:00

Bill Wilson

26-Nov-01 7:00

I would be suprised to find one. Using it in VC++ is just like using it in VB. Import it, create an instance and call its member functions (just like all other COM objects).

Hope this helps,
Bill

Handle Excel sheet from C++ program

XAlien26-Nov-01 4:24

XAlien

26-Nov-01 4:24

Hi all,
anyone know how to control an Excel sheet (if it is possible), create cells, create table, color it and similar...
thanks a lot. Smile | :)

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