//---------------------------------------------------------------------------
//掛上、卸下hook，并運用內存中共享區塊傳遞hook數據
//---------------------------------------------------------------------------
#include <vcl.h> //原有的頭文件
#include <windows.h> //原有的頭文件
#include <stdio.h> //加入C++字符串的頭文件
#pragma hdrstop
#pragma argsused
//---------------------------------------------------------------------------
//DLL的固定聲明
HHOOK hHook;//掛上的hook handle
HINSTANCE ghInst;//連接文件的模塊handle，固定進程
HWND hAppWnd;//執行此dll的特定exe程序handle__"TMouseHookForm"
//存于內存中，dll和exe共享的結構，用于傳遞捕捉到的hook信息
struct POD
{
char text[256];
//...user可自行擴充此結構成員
} *buf; //指向內存共享區塊的指針
HANDLE maphandle;//共享的內存區塊handle
//---------------------------------------------------------------------------
//符合以C語言編譯的DLL輸出函數
extern "C" __declspec(dllexport) __stdcall void SetHook(void);
extern "C" __declspec(dllexport) __stdcall void RemoveHook(void);
//---------------------------------------------------------------------------
//重載的MouseProc函數，持續送出鼠標全域信息
LRESULT CALLBACK MouseProc(int, WPARAM, LPARAM);
//---------------------------------------------------------------------------
//DLL的構造函數和析構函數
int WINAPI DllEntryPoint(HINSTANCE hinst, unsigned long reason, void*)
{
ghInst = hinst;
//當此DLL被調用或結束
switch(reason)
   {
   case DLL_PROCESS_ATTACH: //此DLL的構造函數
         //取得執行此dll的特定程序handle
         hAppWnd = ::FindWindow("TCallHookForm", 0);
         //打開已經存在的共享內存區域
         maphandle = ::OpenFileMapping( FILE_MAP_WRITE, false, "MyMapName");
         //if(!maphandle) return;
         //轉換成可擦寫的對象指針
         buf = (POD *)::MapViewOfFile( maphandle,
                                       FILE_MAP_READ | FILE_MAP_WRITE,
                                       0, 0, 0 );
         //if(!buf) return;
         break;
   case DLL_PROCESS_DETACH: //此DLL的析構函數
         //釋放內存區塊
         ::UnmapViewOfFile((void *)buf);
         break;
   }
return 1;
}
//---------------------------------------------------------------------------
//注冊自定義hook到hook鏈中
void __stdcall SetHook(void)
{//若Hook尚未掛到信息鏈中，則將本鼠標信息dll注冊到hook鏈中
if(hHook == NULL)
  {
  hHook = ::SetWindowsHookEx(WH_MOUSE, (HOOKPROC)MouseProc, ghInst, 0);
  //顯示是否掛上hook
  if(hHook == NULL)
      MessageBox(NULL, "Sorry! 無法掛上Hook。", "Hook DLL", MB_OK);
  else
      ::TextOut(GetDC(0),10,10,"掛上Hook。",10);
  }
}
//---------------------------------------------------------------------------
//在hook鏈中，解除自定義的hook
void __stdcall RemoveHook(void)
{//若Hook已經掛上信息鏈，則卸下此Hook信息
if(hHook != NULL)
  {
  if(::UnhookWindowsHookEx(hHook) != FALSE)
    {
    hHook = NULL;
    ::TextOut(GetDC(0),50,10,"釋放Hook。",10);
    }
  else
    MessageBox(NULL, "Sorry! 無法釋放Hook。", "Hook DLL", MB_OK);
  }
else
  ::TextOut(GetDC(0),80,10,"Hook isn't NULL",16);
}
//---------------------------------------------------------------------------
//重載的MouseProc函數，持續送出鼠標全域信息
LRESULT CALLBACK MouseProc(int nCode, WPARAM wParam, LPARAM lParam)
{
//若未掛上Hook鏈，就交給下一個hook鏈
if(nCode < 0)
   return ::CallNextHookEx(hHook, nCode, wParam, lParam);
//若已經掛上Hook鏈，則檢測鼠標信息