C / C++ / MFC

Re: Need Help With "error LNK2019: unresolved external symbol"

4-Mar-07 21:15

Hi, I'm having a link error problem and I don't know how to fix it.
Please help me out.

error LNK2019: unresolved external symbol _Validate@1068 referenced in
function...........

I use VS2005

I have a static library with the following C++ settings:
/Od /D "WIN32" /D "_DEBUG" /D "_LIB" /D "_UNICODE" /D "UNICODE" /Gm /
EHsc /RTC1 /MDd /Yu"stdafx.h" /Fp"Debug\Licensor.pch" /Fo"Debug\\" /
Fd"Debug\vc80.pdb" /W3 /nologo /c /Wp64 /ZI /TP /errorReport:prompt

It uses __cdecl (/Gd) calling convention.

In the header file, I have
#if __cplusplus
extern "C" {
#endif

__declspec(dllexport) int WINAPI Validate(CHAR szNewKey[], int length, LICENSEDATA licData, LICENSEDATA* extLicData);

#if __cplusplus
}
#endif

I have a win32 project that links to the static library above in order to
call the Validate function. It has the following C++ settings:
/Od /I "..\..\Licensor" /D "WIN32" /D "_DEBUG" /D "_WINDOWS" /D
"VERBOSE" /D "_VC80_UPGRADE=0x0600" /D "_MBCS" /FD /EHsc /MTd /Fp".
\Debug/Temp.pch" /Fo".\Debug/" /Fd".\Debug/" /W4 /nologo /c /ZI /TP /
errorReport:prompt

It too uses __cdecl (/Gd) calling convention.

I'm not sure what to change. Should I be using __stdcall (/Gz) calling
convention for the project? I tried that but no luck either.

Any suggestion? Thanks much.

prasad_som4-Mar-07 21:26

prasad_som

4-Mar-07 21:26

jipai wrote:
In the header file, I have
#if __cplusplus
extern "C" {
#endif

__declspec(dllexport) int WINAPI Validate(CHAR szNewKey[], int length, LICENSEDATA licData, LICENSEDATA* extLicData);

#if __cplusplus
}

Where this function is defined ?

Prasad
Notifier using ATL | Operator new[],delete[][^]

Re: Need Help With "error LNK2019: unresolved external symbol"

jipai4-Mar-07 21:52

Re: Need Help With "error LNK2019: unresolved external symbol"

4-Mar-07 21:52

It's defined in a .cpp file of the static library, something like

extern "C" __declspec(dllexport) int WINAPI Validate(char szKey[], int length, LICENSEDATA licData, LICENSEDATA* extLicData)
{
.
.
// code here
.
.
}

Do I need extern "C" here in the cpp file?

Cedric Moonen4-Mar-07 21:27

Cedric Moonen

4-Mar-07 21:27

jipai wrote:
I have a win32 project that links to the static library above in order to
call the Validate function.

Did you explicitely change your project settings in order to link to this library ? If no, that's your problem.
Open your project properties, go into "Linker" category -> "Input" and add your library to the "Additional Dependencies" list.

Your library must be in one of the library directory (to add it, open the "Linker" category -> "General" and add the folder in "Additional Library Directory").

Cédric Moonen
Software developer

Charting control [v1.1]

Re: Need Help With "error LNK2019: unresolved external symbol"

jipai4-Mar-07 22:54

Re: Need Help With "error LNK2019: unresolved external symbol"

4-Mar-07 22:54

Yes, I did add the static library Licensor.lib to the win32 project Linker -> Input -> Additional Dependencies setting, and the folder to the library path. It didn't complain about library not found. This is the command line:

/OUT:".\Debug\MyApp.exe" /INCREMENTAL /NOLOGO /LIBPATH:"..\chapp\Debug" /MANIFEST /MANIFESTFILE:".\Debug\MyApp.exe.intermediate.manifest" /DEBUG /PDB:"c:\Developer\Projects\MyApp.pdb" /SUBSYSTEM:WINDOWS /MACHINE:X86 /ERRORREPORT:PROMPT odbc32.lib odbccp32.lib Winmm.lib Licensor.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib

Cedric Moonen4-Mar-07 23:05

Cedric Moonen

4-Mar-07 23:05

I just read your first post again. You said that you made a static library ? So why do you export your functions (this is used only for dll's AFAIK) ?

Cédric Moonen
Software developer

Charting control [v1.1]

Re: Need Help With "error LNK2019: unresolved external symbol"

jipai5-Mar-07 14:51

about parallel Port resources

5-Mar-07 14:51

Yes indeed it's a static library. I ran out of idea so I decided to try that, but even without the export it was no use. Apparently, the static library is C++ based, and the win32 app is a C based. So when I tried to add this around the include header in the win32 app, the link error remained.

#ifdef __cplusplus
extern "C" {
#endif

#include "MyHeader.h"

#ifdef __cplusplus
}
#endif

mt_samiei4-Mar-07 21:01

mt_samiei

4-Mar-07 21:01

Dear all.
for one application I want to see which DMA and IRQ is assigned to parallel port.
Does any one know how to extract these data.
Regards
Mahdi

Adding html help to an existing dialog based application

harsh_29614-Mar-07 20:30

Re: Adding html help to an existing dialog based application

4-Mar-07 20:30

hi i downloaded code to add html help from the link
http://www.codeproject.com/useritems/HTMLHelp.asp[^]

and when i run it, its giving an error with respect to the line "HtmlHelp(this->m_hWnd, "scan_help.chm::/getting_.htm", HH_DISPLAY_TOPIC, NULL);"
error is "error C2660: 'CWnd::HtmlHelpA' : function does not take 4 arguments"
any idea on what to be done to run the program so that i can follow that program to link html help to my application

harsha

Hamid_RT4-Mar-07 20:49

Re: Adding html help to an existing dialog based application

4-Mar-07 20:49

Can you show code
Declare of CWnd::HtmlHelp on the MSDN is

virtual void HtmlHelp(
   DWORD_PTR dwData,
   UINT nCmd = 0x000F 
);

WhiteSky

harsh_29614-Mar-07 21:58

Re: Adding html help to an existing dialog based application

4-Mar-07 21:58

void CTestHelpDlg::OnHelp()
{
// TODO: Add your control notification handler code here
HtmlHelp(this->m_hWnd, "scan_help.chm::/getting_.htm", HH_DISPLAY_TOPIC, NULL);

}

and my ".h" file is

// TestHelpDlg.h : header file
//

#if !defined(AFX_TESTHELPDLG_H__4C88ADC9_77D8_4344_ACF6_92E5910070E8__INCLUDED_)
#define AFX_TESTHELPDLG_H__4C88ADC9_77D8_4344_ACF6_92E5910070E8__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

/////////////////////////////////////////////////////////////////////////////
// CTestHelpDlg dialog

class CTestHelpDlg : public CDialog
{
// Construction
public:
CTestHelpDlg(CWnd* pParent = NULL); // standard constructor

// Dialog Data
//{{AFX_DATA(CTestHelpDlg)
enum { IDD = IDD_TESTHELP_DIALOG };
// NOTE: the ClassWizard will add data members here
//}}AFX_DATA

// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CTestHelpDlg)
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
//}}AFX_VIRTUAL

// Implementation
protected:
HICON m_hIcon;

// Generated message map functions
//{{AFX_MSG(CTestHelpDlg)
virtual BOOL OnInitDialog();
afx_msg void OnSysCommand(UINT nID, LPARAM lParam);
afx_msg void OnPaint();
afx_msg HCURSOR OnQueryDragIcon();
afx_msg void OnHelp();
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};

//{{AFX_INSERT_LOCATION}}
// Microsoft Visual C++ will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_TESTHELPDLG_H__4C88ADC9_77D8_4344_ACF6_92E5910070E8__INCLUDED_)

please see the link in my ques for total code..

harsha

Hamid_RT5-Mar-07 5:46

Re: Adding html help to an existing dialog based application

5-Mar-07 5:46

What happens if you use of ::HtmlHelp instead HtmlHelp

WhiteSky

harsh_29616-Mar-07 18:38

Re: Adding html help to an existing dialog based application

6-Mar-07 18:38

error is gone when i put it.. but on clicking Help button in dialog html help page is not opening.. ? any clue on what to do ?

harsha

Hamid_RT6-Mar-07 18:46

Re: Adding html help to an existing dialog based application

6-Mar-07 18:46

See two examples Htmlhelp Forensics[^] and Creating and Using HTML Help in MFC applications
[^] I think they are helpfuls for you Wink | ;)

WhiteSky

harsh_29616-Mar-07 19:52

Re: Adding html help to an existing dialog based application

6-Mar-07 19:52

Creating and Using HTML Help in MFC applications
[^]

i am using this onl.. its not happening ..the error i asked intially is coming even when i download this code and run it directly with out any changes in my comp..not able to figure out whats the problem Smile | :)

harsha

Hamid_RT7-Mar-07 6:58

where and how to write code for SetFont() for Dialog box in VC++?

7-Mar-07 6:58

See CWinApp::HtmlHelp[^] but see About the HTMLHelp API Function on this link(pszFile and uCommand ) Wink | ;)

WhiteSky

Atul234-Mar-07 20:29

Atul23

4-Mar-07 20:29

Hi
All
I want to change font of Dialog box in VC++ 6.0, so how to use SetFont funtion.So anybody have code to change font of dialog box, plz forward me.

Thanks in Advance

WTF | :WTF:

Atul Mahajan

Re: where and how to write code for SetFont() for Dialog box in VC++?

Hamid_RT4-Mar-07 20:53

4-Mar-07 20:53

You aksed this question Change default dialog font[^] was not your answer?

WhiteSky

DB Connection

Krishnatv4-Mar-07 20:09

Krishnatv

4-Mar-07 20:09

while I try to connect Database using DAO , Iam getting this error

Unrecognized database format ' c:\......\ xxx.mdb '

how to connect the Database ?

plz guide me.

Re: DB Connection

Hamid_RT4-Mar-07 20:52