GetProcAddress failed?

Hello everyone,

Here is my below code for the DLL consumer and the DLL itself's code. I am
using LoadLibrary and GetProcAddress to get the function pointer and then
make a call. But statement " StoreDataFp StoreData =
(StoreDataFp)GetProcAddress(hMod,TEXT("StoreData"))" always return 0 for
StoreData. What is the root cause?

DLL Consumer code:
[Code]
// The process code

#include <windows.h>
#include <stdio.h>
 
#define THREADCOUNT 1
#define DLL_NAME TEXT("testdll.dll")

VOID ErrorExit(LPSTR);

typedef BOOL(*StoreDataFp)(DWORD);
typedef BOOL (*GetDataFp)(DWORD*);
 
DWORD WINAPI ThreadFunc(VOID)
{
   int i;

  HMODULE hMod;
  hMod = LoadLibrary(TEXT("testdll.dll"));

  StoreDataFp StoreData = (StoreDataFp)GetProcAddress(hMod,TEXT("StoreData"));

  GetDataFp GetData = (GetDataFp)GetProcAddress(hMod, TEXT("GetData"));

   if(!StoreData(GetCurrentThreadId()))
      ErrorExit("StoreData error");

   for(i=0; i<5; i++)
   {
      DWORD dwOut;
      if(!GetData(&dwOut))
         ErrorExit("GetData error");
      if( dwOut != GetCurrentThreadId())
         printf("thread %d: data is incorrect (%d)\n", GetCurrentThreadId(),
dwOut);
      else printf("thread %d: data is correct\n", GetCurrentThreadId());
      Sleep(0);
   }
   return 0;
}
 
int main(VOID)
{
   DWORD IDThread;
   HANDLE hThread[THREADCOUNT];
   int i;
 
// Load the DLL

   LoadLibrary(DLL_NAME);
 
// Create multiple threads.
 
   for (i = 0; i < THREADCOUNT; i++)
   {
      hThread[i] = CreateThread(NULL, // default security attributes
         0, // use default stack size
         (LPTHREAD_START_ROUTINE) ThreadFunc, // thread function
         NULL, // no thread function argument
         0, // use default creation flags
         &IDThread); // returns thread identifier
 
   // Check the return value for success.
      if (hThread[i] == NULL)
         ErrorExit("CreateThread error\n");
   }
 
   WaitForMultipleObjects(THREADCOUNT, hThread, TRUE, INFINITE);
 
   return 0;
}
 
VOID ErrorExit (LPSTR lpszMessage)
{
   fprintf(stderr, "%s\n", lpszMessage);
   ExitProcess(0);
}
[/Code]

DLL code:
[Code]
// The DLL code

#include <windows.h>

static DWORD dwTlsIndex; // address of shared memory
 
// DllMain() is the entry-point function for this DLL.
 
BOOL WINAPI DllMain(HINSTANCE hinstDLL, // DLL module handle
    DWORD fdwReason, // reason called
    LPVOID lpvReserved) // reserved
{
    LPVOID lpvData;
    BOOL fIgnore;
 
    switch (fdwReason)
    {
        // The DLL is loading due to process
        // initialization or a call to LoadLibrary.
 
        case DLL_PROCESS_ATTACH:
 
            // Allocate a TLS index.
 
            if ((dwTlsIndex = TlsAlloc()) == TLS_OUT_OF_INDEXES)
                return FALSE;
 
            // No break: Initialize the index for first thread.
 
        // The attached process creates a new thread.
 
        case DLL_THREAD_ATTACH:
 
            // Initialize the TLS index for this thread.
 
            lpvData = (LPVOID) LocalAlloc(LPTR, 256);
            if (lpvData != NULL)
                fIgnore = TlsSetValue(dwTlsIndex, lpvData);
 
            break;
 
        // The thread of the attached process terminates.
 
        case DLL_THREAD_DETACH:
 
            // Release the allocated memory for this thread.
 
            lpvData = TlsGetValue(dwTlsIndex);
            if (lpvData != NULL)
                LocalFree((HLOCAL) lpvData);
 
            break;
 
        // DLL unload due to process termination or FreeLibrary.
 
        case DLL_PROCESS_DETACH:
 
            // Release the allocated memory for this thread.
 
            lpvData = TlsGetValue(dwTlsIndex);
            if (lpvData != NULL)
                LocalFree((HLOCAL) lpvData);
 
            // Release the TLS index.
 
            TlsFree(dwTlsIndex);
            break;
 
        default:
            break;
    }
 
    return TRUE;
    UNREFERENCED_PARAMETER(hinstDLL);
    UNREFERENCED_PARAMETER(lpvReserved);
}

extern "C" __declspec(dllexport)BOOL WINAPI StoreData(DWORD dw)
{
   LPVOID lpvData;
   DWORD * pData; // The stored memory pointer

   // Retrieve a data pointer for the current thread
   lpvData = TlsGetValue(dwTlsIndex);

   // If NULL, allocate memory for the TLS slot for this thread
   if (lpvData == NULL)
   {
      lpvData = (LPVOID) LocalAlloc(LPTR, 256);
      if (lpvData == NULL)
         return FALSE;
      if (!TlsSetValue(dwTlsIndex, lpvData))
         return FALSE;
   }

   pData = (DWORD *) lpvData; // Cast to my data type.
   // In this example, it is only a pointer to a DWORD
   // but it can be a structure pointer to contain more complicated data.

   (*pData) = dw;
   return TRUE;
}

extern "C" __declspec(dllexport) BOOL WINAPI GetData(DWORD *pdw)
{
   LPVOID lpvData;
   DWORD * pData; // The stored memory pointer

   lpvData = TlsGetValue(dwTlsIndex);
   if (lpvData == NULL)
      return FALSE;

   pData = (DWORD *) lpvData;
   (*pdw) = (*pData);
   return TRUE;
}
[/Code]

thanks in advance,
George