C / C++ / MFC

21-Mar-06 20:39

Hello everyone,

I think we can use LoadLibrary to load a .dll file and use its published interface. I am wondering whether there are some methods to un-load a library (which is adverse to LoadLibrary)?

thanks in advance,
George

Rick York21-Mar-06 20:48

Rick York

21-Mar-06 20:48

Are you serious ? Have you read the documentation ? It's right there.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wcecoreos5/html/wce50lrfloadlibrary.asp[^]

Roll eyes | :rolleyes:

George_George22-Mar-06 5:41

22-Mar-06 5:41

Thanks Rick!

This link is dealing with how to load a library. But my question is about how to unload a library.

regards,
George

Ștefan-Mihai MOGA21-Mar-06 20:52

Ștefan-Mihai MOGA

21-Mar-06 20:52

You should call FreeLibrary(...) after you loaded a DLL file. For more information check this:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/freelibrary.asp[^]

George_George22-Mar-06 5:42

22-Mar-06 5:42

Hi Mihai,

This method is very useful. After reading through related MSDN documentations, I have two questions about this,

- How to verify that the library is unloaded? How to write a simple program to verify that the library is real unloaded by the application -- maybe I can try to invoke some functions provided by the .dll after unloading it? Do you have any ideas?

- Is the method FreeLibrary Microsoft C++ standard or standard C++ standard? Could it be used in C program?

Thanks a lot!

regards,
George

Ștefan-Mihai MOGA23-Mar-06 2:39

Ștefan-Mihai MOGA

23-Mar-06 2:39

Hi George,

1) the FreeLibrary function is returning a TRUE/FALSE value to verify if it's unloaded, and you shouldn't invoke other function after you unload it (my advice).

2) that's a Microsoft Windows method specific and it's not in the pure C++ language.

George_George24-Mar-06 14:42

how can i get DC of a GDI+ Bitmap

24-Mar-06 14:42

Thanks Mihai,

If I want to use it in pure C++ language, which similar method should I use?

regards,
George

dijesh_ka21-Mar-06 20:27

dijesh_ka

21-Mar-06 20:27

I need help.I am trying to get the dc of a GDI+ Bitmap dirctly

During runtime i am loading the image in Gdiplus::Bitmap m_gdipBmp;
with out showing it dirctly into view i want to get the dc of this bitmap

I have used this code

Gdiplus::Graphics g(m_gdipBmp);
HDC hDC = g.GetHDC();

but i am not getting the proper dc

Compile Win32 codes in VS.NET 2005?

Syouki_kou21-Mar-06 20:22

21-Mar-06 20:22

I have some code which is generate by VC6.0 sp5, it is a SDI based project. When i compile it in VS.NET 2005, there are a lot of errors and warnings, and i don't want to rewrite my code? what should i do then? help me please!
D'Oh! | :doh:

Ștefan-Mihai MOGA21-Mar-06 20:34

Ștefan-Mihai MOGA

21-Mar-06 20:34

Can you please tell me what kind of errors do you get? Maybe I can help you! Smile | :)

Syouki_kou21-Mar-06 21:06

21-Mar-06 21:06

First: I drag the project file XXX.dsw directly to the .NET IDE, it give me a tip to convert this project, i choose yes. After convert it, i press F7 to build the solution, its errors are:
------ Build started: Project: PWSpy, Configuration: Debug Win32 ------
Compiling...
StdAfx.cpp
Compiling...
Gradient.cpp
d:\workshop\file system\all codes\monitor ap\pwspy\gradient.cpp : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss
d:\workshop\file system\all codes\monitor ap\pwspy\gradient.h : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss
d:\workshop\file system\all codes\monitor ap\pwspy\gradient.cpp(179) : error C2065: 'i' : undeclared identifier
MainFrm.cpp
d:\workshop\file system\all codes\monitor ap\pwspy\tballoon.h : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss
d:\workshop\file system\all codes\monitor ap\pwspy\gradient.h : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss
d:\workshop\file system\all codes\monitor ap\pwspy\mainfrm.cpp(88) : error C2440: 'static_cast' : cannot convert from 'void (__thiscall CMainFrame::* )(WPARAM,LPARAM)' to 'LRESULT (__thiscall CWnd::* )(WPARAM,LPARAM)'
None of the functions with this name in scope match the target type
d:\workshop\file system\all codes\monitor ap\pwspy\mainfrm.cpp(89) : error C2440: 'static_cast' : cannot convert from 'BOOL (__thiscall CMainFrame::* )(WPARAM,LPARAM)' to 'LRESULT (__thiscall CWnd::* )(WPARAM,LPARAM)'
None of the functions with this name in scope match the target type
d:\workshop\file system\all codes\monitor ap\pwspy\mainfrm.cpp(90) : error C2440: 'static_cast' : cannot convert from 'void (__thiscall CMainFrame::* )(WPARAM,LPARAM)' to 'LRESULT (__thiscall CWnd::* )(WPARAM,LPARAM)'
None of the functions with this name in scope match the target type
d:\workshop\file system\all codes\monitor ap\pwspy\mainfrm.cpp(94) : error C2440: 'static_cast' : cannot convert from 'void (__thiscall CMainFrame::* )(UINT,LONG)' to 'LRESULT (__thiscall CWnd::* )(WPARAM,LPARAM)'
None of the functions with this name in scope match the target type
d:\workshop\file system\all codes\monitor ap\pwspy\mainfrm.cpp(95) : error C2440: 'static_cast' : cannot convert from 'void (__thiscall CMainFrame::* )(void)' to 'LRESULT (__thiscall CWnd::* )(WPARAM,LPARAM)'
None of the functions with this name in scope match the target type
d:\workshop\file system\all codes\monitor ap\pwspy\mainfrm.cpp(96) : error C2440: 'static_cast' : cannot convert from 'BOOL (__thiscall CMainFrame::* )(UINT,DWORD)' to 'LRESULT (__thiscall CWnd::* )(WPARAM,LPARAM)'
None of the functions with this name in scope match the target type
d:\workshop\file system\all codes\monitor ap\pwspy\mainfrm.cpp(97) : error C2440: 'static_cast' : cannot convert from 'BOOL (__thiscall CMainFrame::* )(UINT,DWORD)' to 'LRESULT (__thiscall CWnd::* )(WPARAM,LPARAM)'
None of the functions with this name in scope match the target type
d:\workshop\file system\all codes\monitor ap\pwspy\mainfrm.cpp(1421) : error C2065: 'nDevIndex' : undeclared identifier
d:\workshop\file system\all codes\monitor ap\pwspy\mainfrm.cpp(1913) : error C2593: 'operator +=' is ambiguous
d:\microsoft vs .net 2005 ide\microsoft visual studio 8\vc\atlmfc\include\cstringt.h(1372): could be 'ATL::CStringT<basetype,stringtraits> &ATL::CStringT<basetype,stringtraits>::operator +=(wchar_t)'
with
[
BaseType=char,
StringTraits=StrTraitMFC_DLL<char>
]
d:\microsoft vs .net 2005 ide\microsoft visual studio 8\vc\atlmfc\include\cstringt.h(1365): or 'ATL::CStringT<basetype,stringtraits> &ATL::CStringT<basetype,stringtraits>::operator +=(unsigned char)'
with
[
BaseType=char,
StringTraits=StrTraitMFC_DLL<char>
]
d:\microsoft vs .net 2005 ide\microsoft visual studio 8\vc\atlmfc\include\cstringt.h(1358): or 'ATL::CStringT<basetype,stringtraits> &ATL::CStringT<basetype,stringtraits>::operator +=(char)'
with
[
BaseType=char,
StringTraits=StrTraitMFC_DLL<char>
]
while trying to match the argument list '(CString, int)'
PWSpy.cpp
d:\workshop\file system\all codes\monitor ap\pwspy\pwspy.cpp(144) : warning C4996: 'CWinApp::Enable3dControls' was declared deprecated
d:\microsoft vs .net 2005 ide\microsoft visual studio 8\vc\atlmfc\include\afxwin.h(4471) : see declaration of 'CWinApp::Enable3dControls'
Message: 'CWinApp::Enable3dControls is no longer needed. You should remove this call.'
PWSpyDoc.cpp
PWSpyView.cpp
TBalloon.cpp
d:\workshop\file system\all codes\monitor ap\pwspy\tballoon.cpp : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss
d:\workshop\file system\all codes\monitor ap\pwspy\tballoon.h : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss
d:\workshop\file system\all codes\monitor ap\pwspy\gradient.h : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss
d:\workshop\file system\all codes\monitor ap\pwspy\tballoon.cpp(163) : warning C4018: '<' : signed/unsigned mismatch
Generating Code...
Creating browse information file...
Microsoft Browse Information Maintenance Utility Version 8.00.50727
Copyright (C) Microsoft Corporation. All rights reserved.
Build log was saved at "file://d:\WorkShop\File System\All Codes\MONITOR AP\PWSpy\Debug\BuildLog.htm"
PWSpy - 10 error(s), 9 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

RChin21-Mar-06 23:40

RChin

21-Mar-06 23:40

Syouki_kou wrote:
d:\workshop\file system\all codes\monitor ap\pwspy\mainfrm.cpp(89) : error C2440: 'static_cast' : cannot convert from 'BOOL (__thiscall CMainFrame::* )(WPARAM,LPARAM)' to 'LRESULT (__thiscall CWnd::* )(WPARAM,LPARAM)'
None of the functions with this name in scope match the target type

With regards to the messages of the type I've quoted above, maybe I can help.
I remember getting these when I also moved from VS6 to VS7.1.
The new compiler seems to be a lot stricter when it comes to message function prototypes.
I am assuming these functions are message handlers (used in the ON_MESSAGE macro). The prototype required by 7.1 is :
LRESULT memberFxn( WPARAM, LPARAM ).
With VS6.0, you could get away with this allowing a void or a BOOL return type. Even the WPARAM / LPARAM parameters could be tweeked and the compiler would not complain. VS7+ does not give you this flexiblity anymore.

For these type of errors, you will need to go to these functions and change then to the expected prototype. So for example, for the quoted error above, you will need to change the return type from BOOL to LRESULT.

I would also think that the majority of the other compiler errors have similar solutions.

I Dream of Absolute Zero

Syouki_kou22-Mar-06 16:31

22-Mar-06 16:31

Thanks a lot, i have already fix this trouble, but there is another trouble which is cause by ATL, the errors are:
d:\workshop\file system\all codes\monitor ap\pwcontext\PWFormat.h(33) : error C2787: 'IContextMenu' : no GUID has been associated with this object
d:\workshop\file system\all codes\monitor ap\pwcontext\PWFormat.h(33) : error C2440: 'initializing' : cannot convert from 'DWORD_PTR' to 'const IID *' Conversion from integral type to pointer type requires reinterpret_cast, C-style cast or function-style cast
Generating Code...

This is a simple coding which follow Michael Dunn[^]'s steps,but can't compile under VS.NET 2005.

Syouki_kou21-Jun-06 16:10

21-Jun-06 16:10

This trouble is already fixed! Thanks for your help, everyone! Laugh | :laugh: