Question

动态加载DLL问题 DLL加载成功，可是为什么找不报error C3861: “Add”: 找不到标识符

///
////////////// MyDll1.h ////////////////////////////////////////////////
#ifdef MYLIBAPP

#else

#define MYLIBAPP extern "C" __declspec(dllimport)

#endif

MYLIBAPP int g_nResult;

MYLIBAPP int Add(int nLeft,int nRight);
MYLIBAPP int Sub(int nLeft,int nRight);

///MyDll1.CPP///////////////////////////////////////
#include <Windows.h>
#define MYLIBAPP extern "C" __declspec(dllexport)
#include "MyDll1.h"
int g_nResult;
int Add(int nLeft,int nRight)
{
g_nResult = nLeft+nRight;
return g_nResult;
}
int Sub(int nLeft,int nRight)
{

g_nResult = nLeft -nRight;
return g_nResult;
}

/////////可执行文件
#include <Windows.h>
#include <iostream>
using namespace std;
int main()
{
BOOL LibFlag;
int nLeft = 10,nRight = 20,nResult = 0;
HINSTANCE hInst = LoadLibrary(L"MyDll1.dll");
if(hInst == NULL)
{
GetProcAddress(hInst,"MyDll1.dll");
}
else
{
MessageBox(NULL,L"LoadLaibrary Succeed",L"OK",MB_OK);
}

nResult = Add(nLeft,nRight);
cout<<"The Result is :"<<nResult<<endl;
LibFlag = FreeLibrary(hInst);
if(LibFlag == TRUE)
{
MessageBox(NULL,L"FreeLibrary Succeed",L"OK",MB_OK);
}
else
{
MessageBox(NULL,L"FreeLibrary Failed",L"Error",MB_OK);
}
return 0;
}

PS：MyDll1.dlllk加载成功，亲并放在当前可执行文件目录下

Answer 1

可执行文件：
typedef int (WINAPIV *pfn_Add)( int, int );

int main()
{
....
pfn_Add Add;
....

Add = (pfn_Add)GetProcAddress(hInst,"Add");

....
nResult = (*Add)(nLeft,nRight);
}

Answer 2

GetProcAddress(hInst,"MyDll1.dll");第二个参数是你要调用的函数名称，而不是动态库的名称，应该改成GetProcAddress（hInst,"Add")就对了

Answer 3

在exe程序里面加上#include "MyDll1.h"试试