[VC] 键盘监听demo

原创已于 2024-06-06 13:37:58 修改 · 303 阅读

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#算法 #数据结构 #c++

于 2022-12-11 22:13:24 首次发布

本文介绍了一个Windows平台下的键盘监听程序实现细节。该程序通过GetAsyncKeyState函数检测指定按键的状态变化，并记录按键事件。文章展示了如何使用结构体维护按键状态及长按计数，并通过枚举定义了按键标识。

//#define StartThread(thrFun) CloseHandle(CreateThread(NULL,0,thrFun,NULL,0,NULL))
DWORD WINAPI Thread_listen_key(void *arg)
{
    OutputDebugString("start listenning the keyboard....\n");
    //监听以下按键值的触发
    CONST UCHAR keyMap[] = { VK_UP,VK_DOWN,VK_LEFT,VK_RIGHT,VK_DELETE,VK_END,VK_NEXT,VK_INSERT,VK_HOME,VK_PRIOR };
    uint32_t value = 0;
    int nKeyPressed = 0;
    int keyLen = sizeof(keyMap);
    while (true)
    {
        nKeyPressed = 0;
        value = 0;
        //if (GetKeyState(VK_CONTROL)){}
        for (size_t i = 0; i < keyLen; i++)
        {
            if (GetAsyncKeyState(keyMap[i]))
            {
                nKeyPressed++;
                value |= 1 << i;
            }
        }

        if (nKeyPressed > 0)
        {
            //to do your key event logic here...
            printf("Value=%04X.CNT[%d]\n",value,nKeyPressed );
            OutputDebugString("some key down.");
        }

        Sleep(200);

    }
    return 0;
}



typedef struct TAG_KEY_INFO
{
	uint8_t key_curr;
	uint8_t key_old;
	uint8_t long_cnt;
	uint8_t flag_pressed;
	uint8_t flag_long_dn;
} KeyInfo;

typedef enum  ENUM_KEY_ID 
{
	vk_up,
	vk_down,
	vk_left,
	vk_right,
	vk_delete,
	vk_end,
	vk_next,
	vk_insert,
	vk_home,
	max_touch_key
};
KeyInfo g_key_info[max_touch_key];

void clear_key_flags(int key_id)
{
	if (key_id < 0 || key_id >= max_touch_key)
	{
		for (size_t i = 0; i < max_touch_key; i++)
		{
			g_key_info[i].flag_pressed = 0;
		}
		return;
	}
	g_key_info[key_id].flag_pressed = 0;
}

DWORD WINAPI Thread_listen_key(void* arg)
{
	CString str;
	str.Format(_T("Start specified key listenning...\n"));
	OutputDebugString(str);

	//监听以下按键值的触发，windows自带虚拟键值,位置顺序要和ENUM_KEY_ID一致才行
	CONST UCHAR g_key_index_code[] = { VK_UP,VK_DOWN,VK_LEFT,VK_RIGHT,VK_DELETE,VK_END,VK_NEXT,VK_INSERT,VK_HOME,VK_PRIOR };
	uint32_t key_flags = 0;
	int key_len = sizeof(g_key_index_code);
	int cnt = 0;

	while (true)
	{
		key_flags = 0; //PC端获取键值形成32bits的标志位
		for (int i = 0; i < key_len; i++)
		{
			if (GetAsyncKeyState(g_key_index_code[i]))
			{
				key_flags |= 1 << i;
			}

		}

		for (size_t i = 0; i < max_touch_key; i++)
		{
			if (key_flags & (1 << i))
			{
				g_key_info[i].key_curr = 1;
				g_key_info[i].long_cnt++;
				if (g_key_info[i].key_old == 0)
					g_key_info[i].flag_pressed = 1;
				if (g_key_info[i].long_cnt > (10 * 3))
				{ // N second
					g_key_info[i].long_cnt = 0x00;
					if (g_key_info[i].flag_pressed == 0)
					{
						g_key_info[i].flag_long_dn = 1;
					}
				}
			}
			else
			{
				g_key_info[i].key_curr = 0;
				g_key_info[i].long_cnt = 0;
				g_key_info[i].flag_long_dn = 0; // clear long press when button release!
			}
			g_key_info[i].key_old = g_key_info[i].key_curr;

		}//<< end for
		Sleep(100);

		//todo your key logic...

		if (g_key_info[vk_home].flag_pressed)
		{
			str.Format(_T("RawData=%06X , HomeKey pressed.\n"), key_flags);
			OutputDebugString(str);
		}
		if (g_key_info[vk_end].flag_pressed)
		{
			str.Format(_T("RawData=%06X , EndKey pressed.\n"), key_flags);
			OutputDebugString(str);
		}
		//clear all key flags
		clear_key_flags(-1);
	}
	return 0;
}