hook的简单示例

//----------------------------------------------------------------------------------------------------
extern "C" __declspec(dllexport) void __stdcall SetHook(HWND,bool);
LRESULT CALLBACK HookProc(int nCode,WPARAM wParam,LPARAM lParam)
//----------------------------------------------------------------------------------------------------
static HINSTANCE hInstance;// 应用实例句柄
static HWND hWndMain;// MainForm句柄
static HHOOK hKeyHook;// HOOK句柄
static const myMessage=2000;// 自定义消息号
static const SecondPar=1;// 自定义消息第2参数
//----------------------------------------------------------------------------------------------------
int WINAPI DllEntryPoint(HINSTANCE hinst, unsigned long reason, void* lpReserved)
{hInstance=hinst; return 1; }
//----------------------------------------------------------------------------------------------------
void __stdcall SetHook(HWND hMainWin,bool nCode)
{
if(nCode)// 安放HOOK
{
hWndMain=hMainWin;
hKeyHook=SetWindowsHookEx(WH_JOURNALRECORD,(HOOKPROC)HookProc,hInstance,0);
}
else// 卸下HOOK
UnhookWindowsHookEx(hKeyHook);
}
//----------------------------------------------------------------------------------------------------
LRESULT CALLBACK HookProc(int nCode,WPARAM wParam,LPARAM lParam)
{
EVENTMSG *keyMSG=(EVENTMSG *)lParam;
if((nCode==HC_ACTION)&&(keyMSG->message==WM_KEYUP))
PostMessage(hWndMain,myMessage,(char)(keyMSG->paramL),SecondPar);
// 向调用窗体发消息myMessage和虚拟键码(char)(keyMSG->paramL)
return((int)CallNextHookEx(hKeyHook,nCode,wParam,lParam));
}
//----------------------------------------------------------------------------------------------------

应用代码如下：（调DLL）
//----------------------------------------------------------------------------------------------------
static HINSTANCE hDLL;// DLL句柄
typedef void __stdcall (*DLLFUN)(HWND,bool);
DLLFUN DLLSetHook;
static const myMessage=2000;
static const SecondPar=1;
//----------------------------------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner):TForm(Owner)
{}
//----------------------------------------------------------------------------------------------------
void __fastcall TForm1::FormCreate(TObject *Sender)
{
hDLL=LoadLibrary((LPCTSTR)"Project1.dll"); // DLL文件名：Project1.dll
if(hDLL==NULL)
{ ShowMessage("DLL: 不能加载！程序退出。"); exit(1); }
DLLSetHook =(DLLFUN)GetProcAddress(hDLL,"SetHook");
if(DLLSetHook==NULL)
{ ShowMessage("DLL: 函数没找到！程序退出。"); FreeLibrary(hDLL); exit(1); }
DLLSetHook(this->Handle,true);
}
//----------------------------------------------------------------------------------------------------

void __fastcall TForm1::FormClose(TObject *Sender, TCloseAction &Action)
{
DLLSetHook(NULL,false);// 卸下HOOK
FreeLibrary(hDLL);// 卸下DLL
}
//----------------------------------------------------------------------------------------------------
void __fastcall TForm1::ApplicationEvents1Message(tagMSG &Msg,bool &Handled)
{// BCB5.0 的ApplicationEvents元件
if((Msg.message==myMessage)&&(Msg.lParam==SecondPar))
ShowMessage("收到HOOK按键消息！/n/n 【键虚拟码】："+IntToStr(Msg.wParam));
}
//----------------------------------------------------------------------------------------------------

用 WH_JOURNALRECORD 类型HOOK可简单实现.

转自http://www.qqgb.com/Program/CJJ/Cjjsystem/Program_55981_2.html