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how i create a DLL, correctly?

I want create a DLL, but i read a MSDN library and our examples don't run correctly.

I want "RUN : RUNDLL32 MYDLL,Myfunction".

is Example wrong?

// DLL.cpp : Defines the entry point for the DLL application.
#include "stdafx.h"
__declspec(dllexport) BOOL WINAPI MyFunction (HWND hwnd, LPLONG lpIValue, LPSTR lpszValue)
{
MessageBox(NULL,"Message 1 - Test my DLL. Myfunction","Test",MB_OK);
return 0;
}

BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved )
{
MessageBox(NULL,"Message 2 - Test my DLL, dllmain.","Test",MB_OK);
return TRUE;
}
------------------------------------------------

When i run this example, and RUN: "RUNDLL32 mydll.dll,myfunction", it show "Message 2", but don't show "Message 1 ". It show Error in DLL.dll "Missing entry:Myfunction".

jhance

At first glance your problem is simple. In the RUNDLL32 call you specify:

"Myfunction"

In the function you specify:

"MyFunction"

DLL calls ARE CASE SENSITIVE!!

jkr

make it read

// DLL.cpp : Defines the entry point for the DLL application.
#include "stdafx.h"

extern "C" // <--!!
__declspec(dllexport) BOOL WINAPI MyFunction (HWND hwnd, LPLONG lpIValue, LPSTR lpszValue)
{
MessageBox(NULL,"Message 1 - Test my DLL. Myfunction","Test",MB_OK);
return 0;
}

BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved )
{
MessageBox(NULL,"Message 2 - Test my DLL, dllmain.","Test",MB_OK);
return TRUE;
}

And it should work - I assume you have a .cpp file, so this is necessary to turn off the C++ name mangling...

jkr

Oh, and jhance is of course right, the names are case sensitive also...

venkaiah

Try in this way

#include "stdafx.h"
extern "C" __declspec(dllexport) BOOL MyFunction (HWND hwnd, LPLONG lpIValue, LPSTR lpszValue)
{
MessageBox(NULL,"Message 1 - Test my DLL. Myfunction","Test",MB_OK);
return 0;
}

BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved )
{
MessageBox(NULL,"Message 2 - Test my DLL, dllmain.","Test",MB_OK);
return TRUE;
}
i think this will helps you.

jkr

venkaiah,

this already has been covered...

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jemax

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jhance

Am I the only one who can see that this question has already been answer in full?

jkr

jhance: No, you are not :o)

Without a case-correct spelling, the rundll call won't work, but neither would it with a C++ mangled name as the export...

jhance

It sure would be nice if alexBrasil would come back and attend to his question.....

jkr

Well, this really would be helpful, indeed...