[zz]Windows Mobile 上使用键盘钩子

转自：http://tech.it168.com/msoft/2008-01-03/200801031715485.shtml

【IT168 技术文档】

最近做的项目涉及Wince 按键的Hook操作，需要屏蔽挂机键和一些系统按键。

在Windows中，设置键盘钩子很多人都做过，但是在windows Mobile系统中并没有直接的函数支持。但是我们可以通过使用undocument api来实现。

首先定义一些参数
#define WH_KEYBOARD_LL           20
#define HC_ACTION      0
typedef 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);

typedef struct ...{
    DWORD vkCode;
    DWORD scanCode;
    DWORD flags;
    DWORD time;
    ULONG_PTR dwExtraInfo;
} KBDLLHOOKSTRUCT, *PKBDLLHOOKSTRUCT;

static _SetWindowsHookExW         SetWindowsHookEx;
static _UnhookWindowsHookEx    UnhookWindowsHookEx;
static _CallNextHookEx          CallNextHookEx;   

 

然后是实现的代码，LLKeyboardHookCallbackFunction就是回调函数

BOOL ActivateKBHook(HINSTANCE hInstance, HOOKPROC LLKeyboardHookCallbackFunction)
...{ 
    //we need to manually load these standard Win32 API calls
    //MSDN states that these aren't supported in WinCE

    SetWindowsHookEx        = NULL;
    CallNextHookEx            = NULL;
    UnhookWindowsHookEx        = NULL;

       //从 coredll.dll 获取我们需要的函数

    g_hHookApiDLL = LoadLibrary(_T("coredll.dll"));
    if(g_hHookApiDLL == NULL) 
    ...{
        return FALSE;
    }
    else
    ...{

        SetWindowsHookEx = (_SetWindowsHookExW)GetProcAddress(g_hHookApiDLL, _T("SetWindowsHookExW"));
        if(SetWindowsHookEx == NULL)
        ...{
            
            
            return FALSE;
        }
        else
        ...{
            
            g_hInstalledLLKBDhook = SetWindowsHookEx(WH_KEYBOARD_LL, LLKeyboardHookCallbackFunction, hInstance, 0);
            if(g_hInstalledLLKBDhook == NULL)
            ...{
                
                return FALSE;
            }
        }
        
       
        CallNextHookEx = (_CallNextHookEx)GetProcAddress(g_hHookApiDLL, _T("CallNextHookEx"));
        if(CallNextHookEx == NULL)
        ...{
        
            return FALSE;
        }

      
        UnhookWindowsHookEx = (_UnhookWindowsHookEx)GetProcAddress(g_hHookApiDLL, _T("UnhookWindowsHookEx"));
        if(UnhookWindowsHookEx == NULL) 
        ...{
            return FALSE;
        }
    }

  
    return TRUE;
}

BOOL DeactivateKBHook()
...{
    //unload the hook
    if(g_hInstalledLLKBDhook != NULL)
    ...{
        UnhookWindowsHookEx(g_hInstalledLLKBDhook);
        g_hInstalledLLKBDhook = NULL;
    }

    //unload the coredll.dll
    if(g_hHookApiDLL != NULL)
    ...{
        FreeLibrary(g_hHookApiDLL);
        g_hHookApiDLL = NULL;
    }
    
    //we have terminated gracefully
    return TRUE;
}

 

一般的回调函数是这么写的，BlockKeyList是需要屏蔽的按键列表

 

int CLoginDlg::BlockKeyList[] = {VK_TBACK,VK_TTALK,VK_TEND,VK_THOME};


LRESULT CALLBACK CLoginDlg::LLKeyboardHookCallbackFunction(int nCode, WPARAM wParam, LPARAM lParam) 
...{
    if(nCode >= HC_ACTION)
    ...{
        if(wParam == WM_KEYDOWN || wParam == WM_KEYUP || wParam == WM_LBUTTONDOWN)  
        ...{ 
            

            int countKeyList = ARRAY_SIZEOF(BlockKeyList);

            for(int i=0;i<countKeyList;i++)
            ...{
                if((((KBDLLHOOKSTRUCT*)lParam)->vkCode) == BlockKeyList[i])
                ...{
                    return TRUE;
                }
            }

     
        }
    }

    return CallNextHookEx(g_hInstalledLLKBDhook, nCode, wParam, lParam);
}

最后还有关键的一点，网上有人说 WH_KEYBOARD_LL不需要用DLL就能实现全局钩子，但是我发觉至少在windows mobile的机器上不行，还是要用DLL来实现键盘钩子。

以上的方法在windows mobile 5.0以及6.0上都可以正常使用，如果你只是要屏蔽所有按键的话可以简单的使用EnableHardwareKeyboard函数来实现。

相关例子源码下载： http://www.codeproject.com/KB/mobile/wincekbhook.aspx