Edll.c

/* Replace "dll.h" with the name of your header */
#include "dll.h"
#include <windows.h>
#include <tchar.h>

typedef long (__cdecl * CompressType)(unsigned char *, int *, unsigned char *, int);
typedef long (__cdecl * UncompressType)(unsigned char *, int *, unsigned char *, int);

CompressType Bcompress = NULL;
UncompressType Buncompress = NULL;

DLLIMPORT long compress(unsigned char *a, int *b, unsigned char *c, int d)
{
  return Bcompress(a,b,c,d);
}

DLLIMPORT long uncompress(unsigned char *a, int *b, unsigned char *c, int d)
{
  //沒有報錯, 但預期a會是解密過後的資料, 但結果a是NULL
  return Buncompress(a,b,c,d);
}

BOOL WINAPI DllMain(HINSTANCE hModule,DWORD fdwReason,LPVOID lpvReserved)
{
  switch(fdwReason)
  {
    case DLL_PROCESS_ATTACH:
    HINSTANCE cps = LoadLibrary(_T("B.dll"));
    Bcompress = (CompressType) GetProcAddress(cps, "compress");
    Buncompress = (UncompressType) GetProcAddress(cps, "uncompress");
    break;
  }
  return TRUE;
}