为什么GetProcAddress不工作? [英] Why GetProcAddress doesn't work?
问题描述
首先,我创建一个名为 SimpleDll.dll
的简单DLL,其头文件:
First, I create a simple dll called SimpleDll.dll
, its head file:
// SimpleDll.h
#ifdef MYLIBAPI
#else
#define MYLIBAPI __declspec(dllimport)
#endif
MYLIBAPI int Add(int a. int b);
其源代码:
// SimpleDll.c
#include <windows.h>
#define MYLIBAPI __declspec(dllexport)
#include "SimpleDll.h"
int Add(int a, int b)
{
return a + b;
}
然后我在另一个项目中调用它,它工作正常:
Then I call it in another project, and it works fine:
// TestSimpleDll.c
#include "stdafx.h"
#include <windows.h>
#include "SimpleDll.h"
#pragma comment(lib, "SimpleDll.lib")
int _tmain(int argc, _TCHAR* argv[])
{
printf("%d", Add(10, 30)); // Give the expected result 40
return 0;
}
但是,当我调用 GetProcAddress
得到它的地址,它不工作!
However, when I call GetProcAddress
to get it's address, it doesn't work!
// TestSimpleDll2.c
#include "stdafx.h"
#include <windows.h>
#include "SimpleDll.h"
#pragma comment(lib, "SimpleDll.lib")
int _tmain(int argc, _TCHAR* argv[])
{
printf("%d", Add(10, 30)); // Give the expected result 40
HMODULE hModule = GetModuleHandleA("SimpleDll.dll"); // hModule is found
PROC add_proc = GetProcAddress(hModule, "Add"); // but Add is not found !
// add_proc is NULL!
return 0;
}
感谢您的协助。 (PS:我在Windows7上使用VS2010)
更新:
这是Depedency Walker为显示的SimpleDll.dll
档案:
Thanks for your help. (PS: I use VS2010 on Windows7)
Update:
This is what the depedency walker show for the SimpleDll.dll
file:
>
推荐答案
如果您要导出GetProcAddress的名称,则应使用.def文件。否则,您将必须处理c ++名称错误和符号装饰。
You should use a .def file if you want to export the name for GetProcAddress. Otherwise you will have to deal with c++ name mangling and with symbol decorations.
您可以通过将函数声明为 externC
来避免损坏,但避免装饰的唯一方法是要使用.DEF文件。
You can avoid mangling by declaring your function as extern "C"
, but the only way to avoid decorations is to use a .DEF file.
还有一件事 - 在Dependency walker中 - 使用F10在修饰和未修饰的名称之间切换。
One more thing - in Dependency walker - use F10 to toggle between decorated and undecorated names.
这篇关于为什么GetProcAddress不工作?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!