char**之DLL實作－ooieueioo的部落格

今天收到一個任務

任務內容是製作DLL讓主程式可以呼叫

因此就用char**來實作吧

1. DLL端的lib.def需定義函式名稱

LIBRARY LIB
EXPORTS
add @ 1
Manufacture @ 2
model @ 3

2. DLL端的程式碼中須增加函式lib.cpp，當主程式呼叫將會回傳char*

char*_stdcall Manufacture(char **str)
{
//*str = "abc";
//strcpy(str,"abc");
return *str;
}

char*_stdcall model(char ** str)
{
//*str = "abc";
//strcpy(str,"abc");
return *str;
}

主程式端

#include "stdafx.h"
#include "windows.h"

typedef char* (_stdcall * lpManufactureFun)(char**);
typedef char* (_stdcall * lpmodelFun)(char**);

int main(int argc, char* argv[])
{
HINSTANCE hDll;
lpManufactureFun ManufactureFun;
lpmodelFun modelFun;

hDll = LoadLibrary("XXX.dll");
if (hDll != NULL)
{
   ManufactureFun = (lpManufactureFun)GetProcAddress(hDll,"Manufacture");
   if(ManufactureFun != NULL)
   {
      char *a = "you_name";
      char result = (char)ManufactureFun(&a);
      printf("address of a : %d\n", &a);
      printf("Manufacture == %s\n", a);
      //printf("\ncall add in dll:%d",result);
   }
   modelFun = (lpmodelFun)GetProcAddress(hDll,"model");
   if(modelFun != NULL)
   {
      char *a = "my_name";
      char result = (char)modelFun(&a);
      printf("address of a : %d\n", &a);
      printf("model == %s\n", a);
      //printf("\ncall add in dll:%d",result);
   }