如何使键盘钩子跨进程全局化 [英] How to make a keyboard hook global across processes

问题描述

我正在尝试创建一个实用的按键应用程序，以便我可以执行诸如终止预编程进程或启动某些操作之类的操作.我想我应该在任何应用程序中按住 cmd，然后输入一个 4 位数的命令键，这样我就可以在编程、调试观看视频等时快速启动或终止任何东西.

I am trying to create a utility keystroke app so i can do things like kill a preprogrammed process or launch something. I am thinking I should hold cmd in any app, then type in a 4 digit command key so I can launch or kill anything quickly while programming, debugging watching a video, etc.

我想出了如何获得键盘回调，但是无论出于何种原因，一旦我单击进入另一个应用程序，我的击键实用程序就不再接收任何键.即使我单击回到我的控制台窗口或 msvc，我也不会收到任何输入.这是除非它是全局的，那么我如何将钩子设置为全局?

I figured out how to get the keyboard callback, but for whatever reason once I click into another app, my keystroke util receives no more keys. Even if I click back to my console window or msvc, I will not receive any input. This is unless its global, so how do I set the hook to be global?

我的代码是

int main()
{
    hook = SetWindowsHookEx(WH_KEYBOARD, KeyboardProc, GetModuleHandle(0), 0);
    MSG msg;
    while(GetMessage(&msg, NULL, 0, 0) > 0)
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    UnhookWindowsHookEx(hook);
}

推荐答案

为了让所有进程都可以访问您的键盘钩子，必须将它放在一个 DLL 中，然后该 DLL 将被加载到每个进程的地址空间中.要记住的一件重要事情是，由于 DLL 的每个实例都在单独的进程中加载​​，因此每个实例都将拥有自己的 DLL 中任何全局变量的副本.如果需要在这些实例之间共享数据，最简单的方法是在 DLL 中创建共享数据段.以下代码来自我编写的一个RSI监控程序.

In order for your keyboard hook to be accessible from all processes, it has to be placed in a DLL which will then be loaded into each process' address space. One important thing to keep in mind is that since each instance of the DLL is loaded in a separate process, each will have its own copy of any global variables in the DLL. If you need to share data between these instances, the simplest way is to create a shared data segment in the DLL. The following code is from an RSI monitoring program I wrote.

//
// some data will be shared across all
// instances of the DLL
//
#pragma comment(linker, "/SECTION:.SHARED,RWS")
#pragma data_seg(".SHARED")
int iKeyCount = 0;
HHOOK hKeyboardHook = 0;
HHOOK hMouseHook = 0;
#pragma data_seg()

//
// instance specific data
//
HMODULE hInstance = 0;

//
// DLL load/unload entry point
//
BOOL APIENTRY DllMain(HANDLE hModule, 
                      DWORD  dwReason, 
                      LPVOID lpReserved)
{
   switch (dwReason)
   {
   case DLL_PROCESS_ATTACH :
      hInstance = (HINSTANCE) hModule;
      break;

   case DLL_THREAD_ATTACH :
      break;

   case DLL_THREAD_DETACH :
      break;

   case DLL_PROCESS_DETACH :
      break;
   }
   return TRUE;
}

//
// keyboard hook
//
LRESULT CALLBACK KeyboardProc(int code,       // hook code
                              WPARAM wParam,  // virtual-key code
                              LPARAM lParam)  // keystroke-message information
{
   if ((lParam & 0x80000000) != 0)
   {
      ++iKeyCount;
   }
   return CallNextHookEx(hKeyboardHook, code, wParam, lParam);
}

//
// mouse hook
//
LRESULT CALLBACK MouseProc(int code,       // hook code
                           WPARAM wParam,  // message identifier
                           LPARAM lParam)  // mouse coordinates
{
   switch (wParam)
   {
   case WM_LBUTTONDOWN :
   case WM_MBUTTONDOWN :
   case WM_RBUTTONDOWN :
   case WM_LBUTTONDBLCLK :
   case WM_MBUTTONDBLCLK :
   case WM_RBUTTONDBLCLK :
      ++iKeyCount;
      break;
   }
   return CallNextHookEx(hMouseHook, code, wParam, lParam);
}

//
// install keyboard/mouse hooks
//
void KBM_API InstallHooks(void)
{
   hKeyboardHook = SetWindowsHookEx(WH_KEYBOARD, KeyboardProc, hInstance, 0);
   hMouseHook = SetWindowsHookEx(WH_MOUSE, MouseProc, hInstance, 0);
}

//
// remove keyboard/mouse hooks
//
void KBM_API RemoveHooks(void)
{
   UnhookWindowsHookEx(hKeyboardHook);
   UnhookWindowsHookEx(hMouseHook);
   hKeyboardHook = hMouseHook = 0;
}

//
// retrieve number of keystrokes
//
int KBM_API FetchKeyCount(bool bClear)
{
   int kc = iKeyCount;
   if (bClear)
      iKeyCount = 0;
   return kc;
}

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