Windows的钩子机制详解

HHOOK SetWindowsHookEx( int idHook, HOOK_PROC lpfn, HINSTANCE hMod,DWORD dwThreadID);

BOOL UnhookWindowsHookEx( HHOOK hhk );

LRESULT CallNextHookEx( HHOOK hhk, int nCode, WPARAM wParam, LPARAM lParam );

#pragma data_seg("PublicData")
HHOOK hhook=NULL; //全局共享数据
#pragma data_seg()

extern "C" LRESULT CALLBACK MouseProc(int code,
WPARAM wParam,LPARAM lParam); //钩子处理函数
extern "C" BOOL WINAPI StartHook(); //启动钩子函数
extern "C" BOOL WINAPI StopHook(); //撤销钩子函数
extern "C" int WINAPI GetResult(); //取得鼠标单击次数的函数

#include "stdafx.h"
#include <afxdllx.h>
#include "spyhook.h"
……//省略部分机器生成代码
#pragma data_seg("PublicData") //定义全局数据段
HHOOK hhook=NULL; //钩子句柄
HINSTANCE pInstance=NULL; //钩子模块句柄
UINT MouseClick=0; //记录鼠标单击次数的变量
#pragma data_seg()
……//省略部分机器生成代码
extern "C" int APIENTRY
DllMain(HINSTANCE hInstance, DWORD dwReason, LPVOID lpReserved)
{ if (dwReason == DLL_PROCESS_ATTACH)
{ ……//省略部分机器生成代码
new CDynLinkLibrary(SpyDLL);
pInstance=hInstance; //取得模块句柄
}
else if (dwReason == DLL_PROCESS_DETACH)
{ TRACE0("SPY.DLL Terminating!\n");
AfxTermExtensionModule(SpyDLL);
}
return 1; 
}
extern "C" LRESULT CALLBACK MouseProc(int code,WPARAM wParam,
LPARAM lParam) //钩子处理函数
{ if (code < 0) //若code<0，直接调用CallNextHookEx返回
return CallNextHookEx(hhook, code, wParam, lParam);
if(wParam==WM_LBUTTONDOWN)
{ MouseClick++; //记录鼠标单击次数
}
return CallNextHookEx(hhook, code, wParam,lParam);
}

extern "C" BOOL WINAPI StartHook() //启动钩子函数
{ hhook=SetWindowsHookEx(WH_MOUSE,MouseProc,pInstance,0); //挂上钩子
if(hhook!=NULL)
return TRUE;
else return FALSE;
}
extern "C" BOOL WINAPI StopHook() //撤销钩子函数
{ return UnhookWindowsHookEx(hhook); //撤销钩子
}
extern "C" int WINAPI GetResult() //返回鼠标单击次数
{ return MouseClick;
}

LIBRARY "SPY"
DEs criptION 'SPY Windows Dynamic Link Library'
EXPORTS
StartHook @1
StopHook @2
GetResult @3

#include "hook.h"
……//省略部分机器生成代码
void CMainFrame::OnStartSpy() //"启动"菜单项的响应函数
{ StartHook();
}

void CMainFrame::OnReleaseSpy() //"撤销"菜单项的响应函数
{ StopHook();
}

void CMainFrame::OnGet() //"取出"菜单项的响应函数
{ int Result=GetResult();
char buffer[40];
wsprintf(buffer,"在程序运行期间，你共单击鼠标%d次",Result);
::MessageBox(this->m_hWnd,buffer,"Message",MB_OK); 
}