#ifndef  _ULHOOK_H__  

#define _ULHOOK_H__  

#include <Windows.h>  

#pragma once  

class CULHook  

{  

public:  

    CULHook(LPSTR lpszModName, LPSTR lpszFuncNme, PROC pfnHook);  

    ~CULHook(void);  

    //取消掛鉤  

    void UnHook();  

    //重新掛鉤  

    void ReHook();  

protected:  

    PROC m_pfnOrig;  

    BYTE m_btNewBytes[8];  

    BYTE m_btOldBytes[8];  

    HMODULE m_hModule;  

};  

#endif

.cpp源文件如下：

復(fù)制代碼代碼如下:

#include "ULHook.h"  

CULHook::CULHook(LPSTR lpszModName, LPSTR lpszFuncNme, PROC pfnHook)  

{  

    BYTE btNewBytes[] = {0xB8, 0x00, 0x00,0x40,0x00,0xFF,0xE0,0x00};  

    memcpy(m_btNewBytes, btNewBytes, 8);  

    *(DWORD*)(m_btNewBytes+1) = (DWORD)pfnHook;  

    m_hModule = ::LoadLibraryA(lpszModName);  

    if (NULL == m_hModule)  

    {  

        m_pfnOrig = NULL;  

        return;  

    }  

    m_pfnOrig = (PROC)::GetProcAddress(m_hModule, lpszFuncNme);  

    if (NULL != m_pfnOrig)  

    {  

        MEMORY_BASIC_INFORMATION mbi = {0};  

        DWORD dwOldProtect;  

        ::VirtualQuery(m_pfnOrig, &mbi, sizeof(mbi));  

        ::VirtualProtect(m_pfnOrig, 8, PAGE_READWRITE, &dwOldProtect);  

        memcpy(m_btOldBytes, m_pfnOrig, 8);  

        ::WriteProcessMemory(GetCurrentProcess(), (VOID*)m_pfnOrig, m_btNewBytes, 8, NULL);  

        ::VirtualProtect(m_pfnOrig, 8, dwOldProtect, NULL);  

    }  

}  

CULHook::~CULHook(void)  

{  

    UnHook();  

    if (m_hModule!=NULL)  

    {  

        ::FreeLibrary(m_hModule);  

    }  

}  

void CULHook::UnHook()  

{  

    if (m_pfnOrig != NULL)  

    {  

        MEMORY_BASIC_INFORMATION mbi = {0};  

        DWORD dwOldProtect;  

        ::VirtualQuery(m_pfnOrig, &mbi, sizeof(mbi));  

        ::VirtualProtect(m_pfnOrig, 8, PAGE_READWRITE, &dwOldProtect);  

        ::WriteProcessMemory(GetCurrentProcess(), (VOID*)m_pfnOrig, m_btOldBytes, 8, NULL);  

        ::VirtualProtect(m_pfnOrig, 8, dwOldProtect, NULL);  

    }  

}  

void CULHook::ReHook()  

{  

    if (m_pfnOrig != NULL)  

    {  

        MEMORY_BASIC_INFORMATION mbi = {0};  

        DWORD dwOldProtect;  

        ::VirtualQuery(m_pfnOrig, &mbi, sizeof(mbi));  

        ::VirtualProtect(m_pfnOrig, 8, PAGE_READWRITE, &dwOldProtect);  

        ::WriteProcessMemory(GetCurrentProcess(), (VOID*)m_pfnOrig, m_btNewBytes, 8, NULL);  

        ::VirtualProtect(m_pfnOrig, 8, dwOldProtect, NULL);  

    }  

}