实现检测系统按键和模拟系统按键

1.需求分析

一用户要求实现输入某个按键时，能接连触发多个其他按键，类似按键精灵那种，这里对用户的用途保密。这里牵涉到两个问题，1.检测键盘输入 2.模拟键盘输入

2.解决方案

采用键盘钩子和模拟键盘按键解决

3.代码部分

LPDWORD     g_lpdwVirtualKey = NULL;        // Keycode 数组的指针
int         g_nLength = 0;                  // Keycode 数组的大小
BOOL        g_bDisableKeyboard = FALSE;     // 是否屏蔽整个键盘
HINSTANCE   g_hInstance = NULL;             // 模块实例句柄
HHOOK       g_hHook = NULL;                 // 钩子句柄
HWND        g_hMainHwnd  = NULL;            //这个是传过来的窗口句柄
UINT        g_nCallbackMsg = 0;             //回调的消息

LRESULT CALLBACK LowLevelKeyboardProc(int nCode, WPARAM wParam, LPARAM lParam)
{
    if (nCode == HC_ACTION)
    {
        KBDLLHOOKSTRUCT* pStruct = (KBDLLHOOKSTRUCT*)lParam;

        if (g_hMainHwnd != NULL && ((UINT)wParam == WM_KEYDOWN))
        {
            //IsVisible();
            //HWND hActiveWindow = GetActiveWindow();
            if (::IsWindowVisible(g_hMainHwnd))
            {
                LPDWORD tmpVirtualKey = g_lpdwVirtualKey;
                for (int i = 0; i < g_nLength; i++)
                {
                    if (pStruct->vkCode == *tmpVirtualKey++)
                    {
                        //这里不返回还是要搞上去的
                        ::PostMessage(g_hMainHwnd, g_nCallbackMsg, wParam, pStruct->vkCode);
                        //return TRUE;
                    }
                }
            }
        }
    }

    // 传给系统中的下一个钩子
    return CallNextHookEx(g_hHook, nCode, wParam, lParam);
}

/********************************************************************/
/* 开始获取键盘按键消息                                               */
/*                                                                  */
/* 参数:                                                          */
/*          hWnd                    依赖窗口的句柄                 */
/*          nCallbackMsg            回调消息                        */
/*          lpdwVirtualKey          Keycode 数组的指针               */
/*          nLength                 Keycode 数组的大小               */
/*                                                                  */
/* 返回值: TRUE 成功, FALSE 失败                                   */
/********************************************************************/
BOOL StartMaskKey(HWND hWnd, UINT nCallbackMsg, LPDWORD lpdwVirtualKey, int nLength)
{
    // 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
    if (g_lpdwVirtualKey != NULL)
    {
        free(g_lpdwVirtualKey);
        g_lpdwVirtualKey = NULL;
    }

    g_lpdwVirtualKey = (LPDWORD)malloc(sizeof(DWORD) * nLength);
    LPDWORD tmpVirtualKey = g_lpdwVirtualKey;
    for (int i = 0; i < nLength; i++)
    {
        *tmpVirtualKey++ = *lpdwVirtualKey++;
    }
    g_nLength = nLength;
    g_hMainHwnd = hWnd;
    g_nCallbackMsg = nCallbackMsg;

    // 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;
}

/********************************************************************/
/* 停止获取键盘消息                                                 */
/*                                                                  */
/* 参数:  (无)                                                 */
/*                                                                  */
/* 返回值: TRUE 成功, FALSE 失败                                   */
/********************************************************************/
BOOL StopMaskKey()
{
    // 卸载钩子
    if (UnhookWindowsHookEx(g_hHook) == 0) 
    {
        if (g_lpdwVirtualKey)
        {
            free(g_lpdwVirtualKey);
            g_lpdwVirtualKey = NULL;
        }
        return FALSE;
    }
    g_hHook = NULL;
    if (g_lpdwVirtualKey)
    {
        free(g_lpdwVirtualKey);
        g_lpdwVirtualKey = NULL;
    }
    return TRUE;
}

//模拟键盘按键
keybd_event(VK_RETURN, 0, 0, 0);
keybd_event(VK_RETURN, 0, KEYEVENTF_KEYUP, 0);