dll调用例子

 

调用DLL
_declspec(dllexport) int add(int a,int b)
{
 return a+b;
}
//////////
 HINSTANCE hInst;
 hInst=LoadLibrary("danny.dll");
 typedef int (*ADDPROC)(int a,int b);

 ADDPROC Add=(ADDPROC)GetProcAddress(hInst,MAKEINTRESOURCE(1));
 if(!Add)
 {
  MessageBox("获取函数地址失败！");
  return;
 }
 CString str;
 str.Format("5+3=%d",Add(5,3));
 MessageBox(str);

 

 

 

1.模块定义

dannyboy.def文件：

LIBRARY mydllname
EXPORTS
SetPortDown  @1
SetPortUp  @3
FirstScan  @4
BeginScan  @5  
SEGMENTS
MySec READ WRITE SHARED

 

dannyboy.cpp源文件：

#pragma data_seg("MySec")
int g=90;
#pragma data_seg()

#pragma comment(linker,"/section:MySec,RWS")

/*
BOOL WINAPI DllMain(
  HINSTANCE hinstDLL,  // handle to the DLL module
  DWORD fdwReason,     // reason for calling function
  LPVOID lpvReserved   // reserved
)
{

return 1;
}*/

int SetPortDown(int a)
{
return g+a;
}
int SetPortUp(int a)
{
 return g+a;
} 

int FirstScan(void)
{
 return 1;
}
void BeginScan(void)
{
AfxMessageBox("");
}

 

 

2.c语言
BOOL APIENTRY DllMain( HANDLE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
 )
{
    return TRUE;
}
extern "C" __declspec(dllexport) int myadd(int a,int b);
myadd(int a,int b)
{
 AfxMessageBox("1");
 return a+b;

}

 

调用：

#include "windows.h"
#include "iostream.h"

typedef int (*fun)(int a);

int main(int argc, char* argv[])
{
 
HINSTANCE h=LoadLibrary("C:\\Program Files\\Microsoft Visual Studio\\MyProjects\\dannyboy\\Debug\\dannyboy.dll");
if(h==NULL)return 1;
fun add=(fun)GetProcAddress(h,"SetPortDown");
if(add!=NULL)cout<<add(3);
return 0;
}