禁用键盘但让我的程序仍然知道何时按下了一个键

Question

我想用 C 编写一个程序来禁用整个键盘，但继续在我的程序中接收输入。

我尝试使用BlockInput()，但它也阻塞了鼠标，我的程序无法获取键盘输入。

换句话说，我想捕获键盘事件并在它们被其他程序处理之前禁用它们。

例如：

当我运行我的程序并尝试在我的 browser/notepad 中写入时，什么也不会显示（就像键盘不工作），但我仍然可以写入用户写的文件。

这可能吗？

Answer 1

除了需要在注释中使用hooks，还需要根据虚拟键码模拟字符串输出到控制台。并且需要检测鼠标的焦点是在记事本上还是在浏览器上。

这是一个代码示例：

#include <Windows.h>
#include <iostream>

using namespace std;

HHOOK keyboardHook;

LRESULT __stdcall KEYHookCallback(int nCode, WPARAM wParam, LPARAM lParam)
{
    int num[] = { 0x41,0x42,0x43,0x44 ,0x45 ,0x46 ,0x47 ,0x48 ,0x49 ,0x4A ,0x4B ,0x4C ,0x4D ,0x4E ,0x4F,
                    0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,0x58,0x59,0x5A,0x20};
    const char *ch[] = { "A","B", "C", "D", "E", "F", "G", "H","I", "J", "K", "L", "M", "N",
                     "O","P", "Q", "R", "S", "T", "U" ,"V","W", "X", "Y", "Z"," "};
    if (nCode >= 0)
    {
        switch (wParam)
        {
        case WM_KEYDOWN:
        {
            HANDLE stdOut = GetStdHandle(STD_OUTPUT_HANDLE);
            DWORD written = 0;
            KBDLLHOOKSTRUCT* kbdStruct = (KBDLLHOOKSTRUCT*)lParam;

            if (stdOut == NULL || stdOut == INVALID_HANDLE_VALUE)
            {
                cout << "error handle" << endl;
                return 0;
            }
            POINT pntCurrentCursor;
            GetCursorPos(&pntCurrentCursor);
            HWND h = FindWindow("Notepad", NULL);
            HWND h2 = FindWindowEx(h, 0, "Edit", NULL);
            HWND h1 = WindowFromPoint(pntCurrentCursor);            
            if(h1 == h2)
            {                                                                 
                for (int i = 0; i < sizeof(num) / sizeof(int); i++)
                {
                    if (kbdStruct->vkCode == num[i])
                    {
                        WriteConsole(stdOut, ch[i], 1, &written, NULL);
                    }
                }
            }                    
            return 1;
        }            
        }
    }
    return CallNextHookEx(keyboardHook, nCode, wParam, lParam);
}

void SetHook()
{
    if (!(keyboardHook = SetWindowsHookEx(WH_KEYBOARD_LL, KEYHookCallback, NULL, 0)))
    {
        cout << "Failed to install keyboardHook hook!" << endl;
    }
}

void ReleaseHook()
{
    UnhookWindowsHookEx(keyboardHook);
}

int main()
{
    SetHook();
    MSG msg;

    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    ReleaseHook();
    return msg.wParam;
}

记事本为测试对象
样本包含26个字符(A~Z)和space条。

调试：

禁用键盘但让我的程序仍然知道何时按下了一个键

Disable keyboard but make my program still know when a key pressed

c

windows

keyboard

winapi

event-handling