DLL加载问题

今天打算研究下白利用的时候出各种问题，复习下dll加载。

1.普通dll文件

int add(int a,int b){return a+b;}

查看输出表为空

2._declspec申明

_declspec(dllexport) int add(int a,int b){    return a+b;}

导出函数名为?add@@YAHHH@Z，产生一个lib文件，需要在link下添加此lib才能extern到函数，或者在调用程序中申明 _declspec(dllimport) int add(int a,int b)

3.添加DEF文件

LIBRARY 3EXPORTSadd

没发生名字改编

4.loader

#include "windows.h"#include "iostream.h"void main(){    HINSTANCE h;    h=LoadLibrary("3.dll");    typedef int (*func_add)(int a,int b);    func_add add=(func_add)GetProcAddress(h,"add");    cout<<add(3,5)<<endl;}

成功加载

5.动态加载message
loader

#include "windows.h"#include "iostream.h"void main(){    HINSTANCE h;    h=LoadLibrary("3.dll");    typedef void (*func_sw)(HWND);    func_sw sw=(func_sw)GetProcAddress(h,"ShowMessage");    sw(FindWindow(NULL,"loader"));}

dll

#include "windows.h"int add(int a,int b){    return a+b;}void ShowMessage(HWND h1){    MessageBox(h1,"1","1",NULL);}

4.dllmain中直接调用MessageBox
dll

#include "windows.h"#include "stdio.h"void ShowMessage();BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved){    switch (fdwReason)    {    case DLL_PROCESS_ATTACH:        MessageBox(NULL,"1","1",MB_OK);        break;    case DLL_PROCESS_DETACH:        break;    }    return TRUE;}void ShowMessage(){    MessageBox(NULL,"1","1",MB_OK);}

成功。。。。。

5.dll中定义函数内部调用MessageBox，dllmain中调用该定义函数
dll

#include "windows.h"#include "stdio.h"void ShowMessage();BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved){    switch (fdwReason)    {    case DLL_PROCESS_ATTACH:        ShowMessage();        break;    case DLL_PROCESS_DETACH:        break;    }    return TRUE;}void ShowMessage(){    MessageBox(NULL,"1","1",MB_OK);}

loader

#include "windows.h"#include "iostream.h"void main(){    HINSTANCE h;    //LoadLibrary("USER32.dll");    h=LoadLibrary("3.dll");    system("sleep");}

成功显示