HOOK使用:全局键盘钩子

// CatchKey.cpp : Defines the entry point for the DLL application. // #define _WIN32_WINNT 0x0500 //设置系统版本，可以使用底层键盘钩子 #define WM_MY_SHORTS (WM_USER + 105) #include "windows.h" //全局变量 LPWORD g_lpdwVirtualKey = NULL; //Keycode 数组的指针 int g_nLength = 0; //Keycode 数组的大小 HINSTANCE g_hInstance = NULL; //模块实例句柄 HHOOK g_hHook = NULL; //钩子句柄 HWND g_hWnd = NULL; BOOL APIENTRY DllMain(HANDLE hModule, DWORD ul_reason_for_call,LPVOID lpReserved) { //保存模块实例句柄 g_hInstance = (HINSTANCE)hModule; //在进程结束或线程结束时卸载钩子 switch (ul_reason_for_call) { case DLL_PROCESS_ATTACH: break; case DLL_THREAD_ATTACH: break; case DLL_PROCESS_DETACH: case DLL_THREAD_DETACH: delete g_lpdwVirtualKey; if (g_hHook != NULL) UnhookWindowsHookEx(g_hHook); break; } return TRUE; } LRESULT CALLBACK LowLevelKeyboardProc(int nCode, WPARAM wParam,LPARAM lParam) { //判断是否是有效按键 if (nCode >= HC_ACTION && wParam==WM_KEYDOWN) { BOOL bctrl = GetAsyncKeyState(VK_CONTROL)>>((sizeof(SHORT) *8)-1); KBDLLHOOKSTRUCT* pStruct = (KBDLLHOOKSTRUCT*)lParam; LPWORD tmpVirtualKey = g_lpdwVirtualKey; if (pStruct->vkCode == 80 && bctrl) PostMessage(g_hWnd,WM_MY_SHORTS,0,1); return TRUE; } //传给系统中的下一个钩子 return CallNextHookEx(g_hHook, nCode, wParam, lParam); } _declspec(dllexport) BOOL WINAPI StartCatch(LPWORD lpdwVirtualKey, int nLength, HWND pWnd) { g_hWnd = pWnd; //如果已经安装键盘钩子则返回 FALSE if (g_hHook != NULL) return FALSE; //将用户传来的 keycode 数组保存在全局变量中 g_lpdwVirtualKey = (LPWORD)malloc(sizeof(WORD) * nLength); LPWORD tmpVirtualKey = g_lpdwVirtualKey; for (int i = 0; i < nLength; i++) { *tmpVirtualKey++ = *lpdwVirtualKey++; } g_nLength = nLength; //安装底层键盘钩子 g_hHook = SetWindowsHookEx(WH_KEYBOARD_LL, LowLevelKeyboardProc, g_hInstance, NULL); if (g_hHook == NULL) return FALSE; return TRUE; } _declspec(dllexport) BOOL WINAPI StopCatch() { //卸载钩子 if (UnhookWindowsHookEx(g_hHook) == 0) return FALSE; g_hHook = NULL; return TRUE; }

 

利用底层的键盘钩子
LRESULT CALLBACK LowLevelKeyboardProc(int nCode, WPARAM wParam,LPARAM lParam)
来拦截 按键的时候

键盘的键按下和弹起时候会发生WM_KEYUP 和 WM_KEYDOWN两个消息，
这两个消息都会被hook，所以如此。

所以需要对 wParam 进行判断  是 WM_KEYDOWN 还是 WM_KEYUP