C / C++ / MFC

samkook1-Nov-05 10:19

1-Nov-05 10:19

I'll explain it better:

I want to declare a variable of type LPCWSTR like this:

LPCWSTR lpInfo;

but I always get an error when I do this

The error: error C2065: 'LPCWSTR' : undeclared identifier

Now the question is : What do I have to do to make this error go away. Do I have to include something or ... ?

Wes Aday1-Nov-05 10:24

Wes Aday

1-Nov-05 10:24

Ah... now that makes a bit more sense. Have you tried changing your project to UNICODE? The 'W' means wide character.

Why is common sense not common?

Never argue with an idiot. They will drag you down to their level where they are an expert.

samkook1-Nov-05 10:26

1-Nov-05 10:26

and how do I change my program to unicode?

Wes Aday1-Nov-05 10:30

Wes Aday

1-Nov-05 10:30

If you are using Visual Studio .NET 2003 then go to Project->Properties. Under the Configuration Properties->General heading, change the Character set option to use UNICODE.

If you are not using VS .NET 2003, I don't know that I can answer your question.

Why is common sense not common?

Never argue with an idiot. They will drag you down to their level where they are an expert.

GflPower1-Nov-05 15:44

GflPower

1-Nov-05 15:44

It(LPCWSTR) declared in WINNT.h File ?

d

Chintoo7231-Nov-05 16:28

Chintoo723

1-Nov-05 16:28

Wes Aday wrote:
Have you tried changing your project to UNICODE? The 'W' means wide character.

Are you sure? I thought defining UNICODE is to convert LPCTSTR to LPCWSTR, but otherwise you can always use LPCWSTR. I have used it like this, may be I included wchar.h?

thanks!

Mircea Puiu1-Nov-05 10:41

Mircea Puiu

1-Nov-05 10:41

See section MBCS and Unicode in the Win32 API of this article at CP:
http://www.thecodeproject.com/string/cppstringguide1.asp?print=true[^]

SkyWalker

Re: LPCWSTR and .net

samkook1-Nov-05 10:46

Re: LPCWSTR problem solve

1-Nov-05 10:46

I already read this article, but it doesn't help me with this problem, it only helped me understand how unicode and multibyte works.

And for the previous answer:

It didn't change anything, but I wanted my program to be in Unicode so that helped.

And I found something weird, windows.h was included in the main .cpp of my application, and if I erase it and put it in the stdafx.h, the lpcwstr is working. But I get error with my messageboxes and the getobject function(wich was generated automatically).

Do you understand something about this?

BTW i'm using a .net project. That seems to cause all the errors because if i make a classic win32 application, it's working.

-- modified at 17:16 Tuesday 1st November, 2005

samkook1-Nov-05 13:21

yahoo mail - rundll32 query

1-Nov-05 13:21

It seems that there is a bug that occur when you include windows.h (I don't know why this include was put in the .cpp by default, but it wasn't including it correctly)

All I had to do is add

#pragma push_macro("GetObject")
#undef GetObject
#pragma push_macro("MessageBox")
#undef MessageBox

at the start of my code and

#pragma pop_macro("GetObject")
#pragma pop_macro("MessagBox")

at the end to make it work.

Chintoo7231-Nov-05 9:42

Chintoo723

1-Nov-05 9:42

Yahoo installs a start menu item to open “yahoo mail”, the shortcut points to:

C:\WINDOWS\system32\RUNDLL32.EXE C:\PROGRA~1\Yahoo!\Common\ymmapi.dll,OpenURL http://mail.yahoo.com/?.redir=ymmapi11

This seems to run iexplore.exe under svchost.exe under system. Does anyone know how this works? what exactly does rundll32.exe do here? Does the DLL have anything to do with the iexplore.exe opening under svchost.exe?

And, why does yahoo do it this way - any benefits?

thanks!

Re: yahoo mail - rundll32 query

Prakash Nadar1-Nov-05 16:20

Prakash Nadar

1-Nov-05 16:20

rundll32.exe is used to "execute" a dll.

Since dll can not live by itself in the memory,it needs a host so windows provides svchost.exe as host for an "executable" dll which is most likely to be ymmapi.dll

-prakash

Re: yahoo mail - rundll32 query

Chintoo7231-Nov-05 16:25

Chintoo723

1-Nov-05 16:25

Thank you. Do you know how to implement a DLL of my own that will work this way?

thanks!

Re: yahoo mail - rundll32 query

Prakash Nadar1-Nov-05 17:34

Prakash Nadar

1-Nov-05 17:34

This [^] & this[^] might be usefull

-prakash

C++, STL, and warning level 4

Jim Crafton1-Nov-05 9:34

1-Nov-05 9:34

I just read John Simmons post about getting his app to compile cleaning at warning level 4.
So, just for kicks I thought I'd try it on a console server app I am currently finishing up. But I get oodles and oodles of warnings from within the STL headers. Is there some other setting you need to use to do this? Is it not possible to have w4 clean code and use STL? This is using VC6 (sp5).

¡El diablo está en mis pantalones! ¡Mire, mire!

Real Mentats use only 100% pure, unfooled around with Sapho Juice(tm)!

SELECT * FROM User WHERE Clue > 0
0 rows returned

Save an Orange - Use the VCF!

Jim Crafton1-Nov-05 9:39

1-Nov-05 9:39

Just as an aside, I've noticed that there is reference to the /Za option, to disable Microsoft language extensions. But if you do this, then you lose the __declspec(__import), and __declspec(__export). Which means, if you do C++, that if you are creating a DLL, you'll need to export the functions by hand through a .def file, right? Isn't that a total nightmare? Does anyone actually do this?

¡El diablo está en mis pantalones! ¡Mire, mire!

Real Mentats use only 100% pure, unfooled around with Sapho Juice(tm)!

SELECT * FROM User WHERE Clue > 0
0 rows returned

Save an Orange - Use the VCF!

C^hris L^osinger1-Nov-05 9:43

C^hris L^osinger

1-Nov-05 9:43

Jim Crafton wrote:
Isn't that a total nightmare? Does anyone actually do this?

it's not really a nightmare. you just put the function names in the .DEF file and compile... i do it all the time.

Cleek | Image Toolkits | Thumbnail maker

Jim Crafton1-Nov-05 9:45

1-Nov-05 9:45

Right but with a C++ DLL (i.e. exporting a C++ class from the DLL), you can't do that - you have to put the name mangled names right? Plus, at least for my project at home, this could amount to several hundred classes (at least).

¡El diablo está en mis pantalones! ¡Mire, mire!

Real Mentats use only 100% pure, unfooled around with Sapho Juice(tm)!

SELECT * FROM User WHERE Clue > 0
0 rows returned

Save an Orange - Use the VCF!

Nemanja Trifunovic1-Nov-05 15:23

Nemanja Trifunovic

1-Nov-05 15:23

Jim Crafton wrote:
Right but with a C++ DLL (i.e. exporting a C++ class from the DLL), you can't do that - you have to put the name mangled names right? Plus, at least for my project at home, this could amount to several hundred classes (at least).

There is a free tool that would automatically export all mangled names into a def file, but I can't remember its name Frown | :(

Anyway, even that is not perfect - you don't want all functions from all classes exported.

[EDIT] I remember now. It is dlltool[^].
[/EDIT]

My programming blahblahblah blog. If you ever find anything useful here, please let me know to remove it.

-- modified at 21:25 Tuesday 1st November, 2005

C^hris L^osinger1-Nov-05 9:41

C^hris L^osinger

1-Nov-05 9:41

a little pragma warning(disable: xxx) magic will help a lot.

Cleek | Image Toolkits | Thumbnail maker

Jim Crafton1-Nov-05 9:43

1-Nov-05 9:43

OK but doesn't that defeat the whole purpose? For example I already do this for warning 4786. Is there a standard list of warnings you can safely ignore for warning level 4?

¡El diablo está en mis pantalones! ¡Mire, mire!

Real Mentats use only 100% pure, unfooled around with Sapho Juice(tm)!

SELECT * FROM User WHERE Clue > 0
0 rows returned

Save an Orange - Use the VCF!

Rob Caldecott1-Nov-05 9:48

Rob Caldecott

1-Nov-05 9:48

I have always been lead to believe that the STL shipped with VC6 is an absolute dog and should be avoided. Whether there is much truth in that or not is up to a decent Google search Smile | :)

I do notice that Scott Meyers excellent Effective STL book contains a whole appendix on working around limitations in the VC6 STL.

I use a lot of STL with VS2003 and always compile at warning level 4. I get one warning for release builds when including, amongst a few others, <vector> (some debug code that is unreachable in release mode). Consequently I have something like this:

#pragma warning(push)
#pragma warning(disable: 4702)
#include <vector>
#pragma warning(pop)

I tend to include a special stdstl.h file in my pre-compiled header, containing all the STL headers my project needs (including some boost headers) so I only need this hack in one place.

I haven't tried a build in VS2005 yet, so maybe this C4702 warning has been dealt with.

The Rob Blog
Google Talk: robert.caldecott

Jim Crafton1-Nov-05 9:53

1-Nov-05 9:53

Hmm, that's a good point! I'd forgotten about pragma push/pop!

¡El diablo está en mis pantalones! ¡Mire, mire!

Real Mentats use only 100% pure, unfooled around with Sapho Juice(tm)!

SELECT * FROM User WHERE Clue > 0
0 rows returned

Save an Orange - Use the VCF!

Jim Crafton1-Nov-05 10:28

1-Nov-05 10:28

Hmm, well I just created a new console project (in vc6) and changed it's setting to Multi Threaded CRT, on warning level 4.

here's the main:

#include "stdafx.h"

#pragma warning (push)
#pragma warning (disable : 4100)
#pragma warning (disable : 4663)
#pragma warning (disable : 4511)
#pragma warning (disable : 4512)
#pragma warning (disable : 4018)
#pragma warning (disable : 4244)


#include <vector>
#pragma warning (pop)


int main(int , char** )
{
	return 0;
}

And this just creates loads of warnings, in fact the very same ones I have turned off!
So now I try turning off the language extensions.
Voila! All the warnings are gone, but now I get 102 errors like:

c:\program files\microsoft visual studio\vc98\include\utility(81) : error C2146: syntax error : missing ';' before identifier 'iterator_category'

Sigh, oh well, it's just not worth fighting with Smile | :)

I can't see how anyone who uses STL, VC6, and creates DLLs that export C++ classes can compile at warning level 4.

¡El diablo está en mis pantalones! ¡Mire, mire!

Real Mentats use only 100% pure, unfooled around with Sapho Juice(tm)!

SELECT * FROM User WHERE Clue > 0
0 rows returned

Save an Orange - Use the VCF!

-- modified at 16:29 Tuesday 1st November, 2005

Nemanja Trifunovic1-Nov-05 15:30

Nemanja Trifunovic

1-Nov-05 15:30

Robert Edward Caldecott wrote:
I haven't tried a build in VS2005 yet, so maybe this C4702 warning has been dealt with.

Apparently, yes[^].

My programming blahblahblah blog. If you ever find anything useful here, please let me know to remove it.