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Look on MSDN - the best way is to Google for function-name site:msdn.microsoft.com. For example - what does CreateFile do? Just Google for CreateFile site:msdn.microsoft.com.
Anyway - as I said to you yesterday[^], you're going about this backwards. Start with the MSDN documentation (which tells you all about the function definitions) and then find the function prototype in the header files (although why even do that except when compiling code?!)
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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I am trying to create a dll. During compilation,i get the folowing linking error.
"error LNK2001: unresolved external symbol"
How can i resolve it?
Thanks,
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Giving more information would help us a lot. What is this symbol ? A variable, a function ? How is it declared ? ...
Please, provide as much useful information as possible.
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It is a function.I declared that function in def file.
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Are you scared to provide useful information or what ? 
Where is this function coming from, how is it defined, .... ?
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Actually the complete error message should be more informative. For instance, it should report what symbol is not resolved. Hence, please have a better look at the error message (and report here if you're still in troubles).
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 the complete error message:
COM.def : error LNK2001: unresolved external symbol GetSignalValue()
Release/COM.lib : fatal error LNK1120: 1 unresolved externals
LINK : fatal error LNK1141: failure during build of exports file
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Is GetSignalValue one of the functions of your library (I suppose it is, however maybe you're using also external libraries)? How is it declared and defined? Please show us the relevant code.
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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I am not using any external libraries.
In .def file:
; COM.def : Declares the module parameters for the DLL.
LIBRARY "COM"
DESCRIPTION 'COM Windows Dynamic Link Library'
EXPORTS
; Explicit exports can go here
; COM.cpp Ordinal Numbers 100 - 110
GetSignalValue() @102
In .cpp file:
// COM.cpp: implementation of the CLogger class.
//
//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "COM_1.h"
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
CCOM::CCOM()
{
}
int FAR PASCAL GetSignalValue(int m_lCurValue)
{
long lReturnValue = m_lCurValue;
m_lCurValue += 10;
return lReturnValue;
}
In .h file:
// COM_1.h: interface for the CCOM class.
//
//////////////////////////////////////////////////////////////////////
class CCOM
{
public:
CCOM();
};
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If you're using a C++ compiler (and probably you areusing it) then you should use the extern "C" construct to avoid C++ symbol mangling.
i.e.
extern "C"
{
int FAR PASCAL GetSignalValue(int m_lCurValue);
}and
extern "C"
{
int FAR PASCAL GetSignalValue(int m_lCurValue)
{
}
}
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 to all. I resolved that error. I declared the function in def as
GetSignalValue().It should be GetSignalValue.
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Roay wrote: int FAR PASCAL GetSignalValue(int m_lCurValue)
Declare that as extern "C" - otherwise, the object file will export the C++ mangled name, not the unmangled name your DEF file expects to see.
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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In COM_1.cpp file,Im having the definition for GetSignalValue() function as follows:
// COM.cpp: implementation of the CLogger class.
//
//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "COM_1.h"
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
CCOM::CCOM()
{
}
int FAR PASCAL GetSignalValue(int m_lCurValue)
{
long lReturnValue = m_lCurValue;
m_lCurValue += 10;
return m_lCurValue;
}
In .def file I declared the function as follows:
; COM.def : Declares the module parameters for the DLL.
LIBRARY "COM"
DESCRIPTION 'COM Windows Dynamic Link Library'
EXPORTS
; Explicit exports can go here
; COM.cpp Ordinal Numbers 100 - 110
GetSignalValue @102
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Hi!
By resolving the external symbol? Seriously, give a bit more detail, "Unresolved external symbol" is like you saying "the linker tells me something's missing". It usually means that you forgot to link to some library or forgot to define a variable you declared and used somewhere...
> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <
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Hi sir, it is "All Power to the Imagination!"
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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These kinds of questions should be the easiest to answer, you just guess some answer, post it and consider the transaction done.
> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <
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Hi
How to set 3D border for Edit control,when creating dynamically?
WS_BORDER gives the control, a rectangular black border.
m_EditCtrl.Create( WS_VISIBLE |WS_TABSTOP| ES_NUMBER |WS_BORDER,
CRect( 81, 244, 122, 264 ),
this , 4500 );
Thanks in advance
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BenjaminBruno wrote: How to set 3D border for Edit control,when creating dynamically?
You have to specify WS_EX_CLIENTEDGE for that
m_Edit.CreateEx( WS_EX_CLIENTEDGE, _T("Edit"), _T(""), WS_CHILD|WS_VISIBLE |WS_TABSTOP| ES_NUMBER ,CRect( 81, 244, 122, 264 ),this , 4500 );
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I have a question regarding sockets. I am trying to write two programs that will establish connection between each other to send and receive massages. One program sets connection the code is the following:
struct in_addr convaddr;
BOOL flag=TRUE;
while (flag)
{
s= socket(AF_INET,SOCK_STREAM,0);
if (s == INVALID_SOCKET)
flag=TRUE;
else
flag=FALSE;
}
addr.sin_family = AF_INET;
addr.sin_port = htons(1026);
if (onemach)
addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
else
{
m_ServerIP=getIP();
convaddr.s_addr=atoi(m_ServerIP);
mip=inet_ntoa(convaddr);
addr.sin_addr.S_un.S_addr = inet_addr(mip);
}
flag=TRUE;
while (flag)
{
if (connect(s, (struct sockaddr *)&addr, sizeof(struct sockaddr))==0)
{
flag=FALSE;
}
else
{
Sleep(500);
}
}
And the other accepts connection:
while (flag)
{
sock= socket(AF_INET,SOCK_STREAM,0);
if (sock == INVALID_SOCKET)
flag=TRUE;
else
flag=FALSE;
}
sin.sin_family = AF_INET;
sin.sin_port = htons(1026);
sin.sin_addr.s_addr = INADDR_ANY;
int err=-1;
while (err==-1)
err=bind( sock, (LPSOCKADDR)&sin, sizeof(sin) );
err=-1;
while (err!=0)
err = listen( sock, SOMAXCONN); //SOMAXCONN defined as 5
SOCKET Recv;
SOCKADDR_IN from;
int fromlen=sizeof(from);
//gets the address and port of remote/distant comp.
Recv=accept(sock,(struct sockaddr*)&from, &fromlen);//waits for not defined time
hostIP=new char [37];
hostIP=inet_ntoa(from.sin_addr);
hostPort=htons(from.sin_port);
the problem is that sometimes it works correct: establishes connection and interchanges the massages and sometimes it can’t establish the connection, even if it gets right ip addresses. I will appreciate it greatly if anyone can help me to find where the error comes or to improve the code. Thanks in advance.
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If you're using WinSock for this, you can get extra error information using WSAGetLastError[^] - I'd suggest you investigate a) which operation fails, and b) what the error code is.
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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Hi all,
How to free unsigned long pointer variable?
Thanks in advance
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how did you allocate memory for it?
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Hello Friends
I m using win32.im creating window based application.I m using WM_GETMINMAXINFO,but how do i know that a window is maximized or minimized?I tried with lparam structure also but i m not getting the specific which tells me that a window is minimized or maximized.
Thanks in advance.
Regards
Yogesh
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yogeshs wrote: but how do i know that a window is maximized or minimized
You will get WM_SYSCOMMAND [^] message when a window is maximized or minimized.
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