Windows Mobile 中的键盘钩子实战

在需要用到SOFT1和SOFT2两个按键的时候， 也尝试了各种方案， 最后还是选个钩子函数， 但是在使用的过程中还是出现了一些问题的， 一些解决了一些还没有。下面有以下网上很多的实现。 且看这个

winceKBhook.h

#ifndef _WINCE_KB_HOOK_H#define _WINCE_KB_HOOK_H//used for passing to SetWindowsHookEx funtion to set a Low level (LL) keyboard hook#define WH_KEYBOARD_LL 20// Define the function types used by hookstypedef LRESULT(CALLBACK* HOOKPROC)(int code, WPARAM wParam, LPARAM lParam);typedef HHOOK (WINAPI *_SetWindowsHookExW)(int, HOOKPROC, HINSTANCE, DWORD);typedef LRESULT(WINAPI *_CallNextHookEx)(HHOOK, int, WPARAM, LPARAM);typedef LRESULT(WINAPI *_UnhookWindowsHookEx)(HHOOK);// For the low level keyboard hook, your keyboards procedures is passed a pointer to KBDLLHOOKSTRUCT instancetypedef struct { DWORD vkCode; DWORD scanCode; DWORD flags; DWORD time; ULONG_PTR dwExtraInfo;} KBDLLHOOKSTRUCT, *PKBDLLHOOKSTRUCT;// Win32 Hook APIs static _SetWindowsHookExW SetWindowsHookEx;static _UnhookWindowsHookExUnhookWindowsHookEx;static _CallNextHookEx CallNextHookEx;bool ActivateKBHook(HINSTANCE hInstance, HOOKPROC LLKeyboardHookCallbackFunction);bool DeactivateKBHook();HRESULT DefHookProc(int, WPARAM, LPARAM);#endif

winceKBhook.cpp

#include "stdafx.h"#include "winceKBhook.h"//globalsHINSTANCE g_hHookApiDLL= NULL;//handle to coredll.dll, where all the hook related APIs are presentHHOOK g_hInstalledLLKBDhook = NULL;//g_hInstalledLLKBDhook represents handle to the installed KB hookbool ActivateKBHook(HINSTANCE hInstance, HOOKPROC LLKeyboardHookCallbackFunction){//we need to manually load these standard Win32 API calls//MSDN states that these aren't supported in WinCESetWindowsHookEx= NULL;CallNextHookEx= NULL;UnhookWindowsHookEx= NULL;//now load the coredll.dllg_hHookApiDLL = LoadLibrary(_T("coredll.dll"));if(g_hHookApiDLL == NULL) {//something is awfully wrong//the dll has to be presentreturn false;}else{//load the SetWindowsHookEx API call//the SetWindowsHookEx function installs an application-defined hook procedure into a hook chain. //You would install a hook procedure to monitor the system for certain types of events.//here we use use the hook to monitor kyeboard eventsSetWindowsHookEx = (_SetWindowsHookExW)GetProcAddress(g_hHookApiDLL, _T("SetWindowsHookExW"));if(SetWindowsHookEx == NULL){//this means that MS has really stopped supporting this API in WinCEreturn false;}else{//install the KB hook//the hande needs to be saved for default processing of the events and to uninstall the hook, once we are done with itg_hInstalledLLKBDhook = SetWindowsHookEx(WH_KEYBOARD_LL, LLKeyboardHookCallbackFunction, hInstance, 0);if(g_hInstalledLLKBDhook == NULL){return false;}}//load CallNextHookEx() API call//the CallNextHookEx function passes the hook information to the next hook procedure in the current hook chain. //we use this call for default processing of events.CallNextHookEx = (_CallNextHookEx)GetProcAddress(g_hHookApiDLL, _T("CallNextHookEx"));if(CallNextHookEx == NULL){return false;}//load UnhookWindowsHookEx() API//the UnhookWindowsHookEx function removes a hook procedure installed in a hook chain by the SetWindowsHookEx function.//we use this call to unistall the hook.UnhookWindowsHookEx = (_UnhookWindowsHookEx)GetProcAddress(g_hHookApiDLL, _T("UnhookWindowsHookEx"));if(UnhookWindowsHookEx == NULL) {return false;}}//all the APIs are loaded and the application is hookedreturn true;}bool DeactivateKBHook(){//unload the hookif(g_hInstalledLLKBDhook != NULL){UnhookWindowsHookEx(g_hInstalledLLKBDhook);g_hInstalledLLKBDhook = NULL;}//unload the coredll.dllif(g_hHookApiDLL != NULL){FreeLibrary(g_hHookApiDLL);g_hHookApiDLL = NULL;}//we have terminated gracefullyreturn true;}HRESULT DefHookProc(int nCode, WPARAM wParam, LPARAM lParam){return CallNextHookEx(g_hInstalledLLKBDhook, nCode, wParam, lParam);}

这个类似的实现网上一抄一大把。 我也搞了一个来实现， 还搞了一个DefHookProc函数， 因为懒得把CallNextHookEx时候要用的HHOOK公开了，所以一样的， hook filter里面就调用DefHookProc就好， 不需要调用CallNextHookEx了，一个参数我帮忙填写好了。

末了， 我尝试的实现了一下filter 函数：

int BlockKeyList[] = {VK_F1,VK_F2};#ifndef HC_ACTION#define HC_ACTION 0#endif //HC_ACTIONLRESULT CALLBACK LLKeyboardHookCallbackFunction(int nCode, WPARAM wParam, LPARAM lParam){ KBDLLHOOKSTRUCT* pHook = (KBDLLHOOKSTRUCT*)lParam; if(nCode >= HC_ACTION) { if( wParam == WM_KEYDOWN && pHook->vkCode == VK_F1) { g_App.onKeyEvent(KEY_EVENT_KEY_PRESS, SL_KEY_SOFT1, lParam); return 1; } else if (wParam == WM_KEYUP && pHook->vkCode == VK_F1) { g_App.onKeyEvent(KEY_EVENT_KEY_RELEASE, SL_KEY_SOFT1, lParam); return 1; } else if (wParam == WM_KEYDOWN && pHook->vkCode == VK_F2) { g_App.onKeyEvent(KEY_EVENT_KEY_PRESS, SL_KEY_SOFT2, lParam); return 1; } else if (wParam == WM_KEYUP && pHook->vkCode == VK_F2) { g_App.onKeyEvent(KEY_EVENT_KEY_RELEASE, SL_KEY_SOFT2, lParam); return 1; } } return CallNextHookEx(g_hInstalledLLKBDhook, nCode, wParam, lParam);}

自己看了应该没有什么问题， 但是实际上跑的是时候发现几次都crash了。 当然这些crash都和Messagebox有关系， 都是弹出Messagebox的时候就程序再没有响应了！！！ 糊涂了，难道是messagebox是不同的线程￥%￥……%， 想来想去还是至少有点， g_App.onKeyEvent如果里面弹出Messagebox这里岂不是阻塞了？？ 可能这样的函数是不允许你阻塞在这里的。 所以决定改了， 用PostMessage发个异步的消息看看。

if (code >= 0) { HWND hWnd; TCHAR szTitle[MAX_LOADSTRING]; // title bar text TCHAR szWindowClass[MAX_LOADSTRING]; // main window class name LoadString(g_hInst, IDS_APP_TITLE, szTitle, MAX_LOADSTRING); LoadString(g_hInst, IDC_SCANLIFE, szWindowClass, MAX_LOADSTRING); //If it is already running, then focus on the window, and exit hWnd = FindWindow(szWindowClass, szTitle); if (hWnd) { if (pHook->vkCode == VK_F1 && wParam == WM_KEYDOWN) { PostMessage(hWnd, WM_KEYDOWN, VK_F1, 0); return true; } else if (pHook->vkCode == VK_F1 && wParam == WM_KEYUP) { PostMessage(hWnd, WM_KEYUP, VK_F1, 0); return true; } else if (pHook->vkCode == VK_F2 && wParam == WM_KEYDOWN) { PostMessage(hWnd, WM_KEYDOWN, VK_F2, 0); return true; } else if (pHook->vkCode == VK_F2 && wParam == WM_KEYUP) { PostMessage(hWnd, WM_KEYUP, VK_F2, 0); return true; } } } return DefHookProc(code, wParam, lParam);

果然一把通过了：） 当然就像开始就说的一样， 还是有问题没有解决， 在Smartphone上有的手机直接SetWindowsHookEx失败！ 这个除了程序签名估计没有什么办法。 anyway 继续探索吧。