如何使用 WH_KEYBOARD 在 LowLevelKeyboardProc 上处理按键 state？

Question

How i could know if the key processed by the LowLevelKeyboardProc is from a WM_KEYDOWN or WM_KEYUP message when using the hook procedure WH_KEYBOARD ?

wParam is returning the value of vkCode instead of WM_KEYDOWN/UP .

I'm using WH_KEYBOARD because I want to intercept only the keypress into the given thread as WH_KEYBOARD_LL only works globally.

LRESULT CALLBACK LowLevelKeyboardProc(int nCode, WPARAM wParam, LPARAM lParam)
{

    if (nCode < 0 || nCode != HC_ACTION)
        return CallNextHookEx(g->KeyboardHook, nCode, wParam, lParam);

    KBDLLHOOKSTRUCT* pKeyBoard = (KBDLLHOOKSTRUCT*)lParam;

    // How to know if the msg is from a WM_KEYDOWN/KEYUP ?

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


int Main()
{
    WNDCLASSEX wc{};
    HWND hWnd = nullptr;
    MSG Msg;

    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = 0;
    wc.lpfnWndProc = WndProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = 0;
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wc.lpszMenuName = NULL;
    wc.lpszClassName = L"test";
    wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

    hWnd = CreateWindowW(L"test", L"test",  WS_OVERLAPPED | WS_CAPTION | WS_MINIMIZEBOX | WS_SYSMENU, CW_USEDEFAULT, CW_USEDEFAULT, 828, 492, nullptr, nullptr, nullptr, nullptr);

    ShowWindow(hWnd, SW_SHOW);
    UpdateWindow(hWnd);

    g->KeyboardHook = SetWindowsHookEx(WH_KEYBOARD, LowLevelKeyboardProc, GetModuleHandle(NULL), GetWindowThreadProcessId(g->hWnd, NULL));

    while (GetMessage(&Msg, NULL, 0, 0) > 0)
    {
        TranslateMessage(&Msg);
        DispatchMessage(&Msg);
    }
    return 0;
}

Answer 1

LRESULT CALLBACK KeyboardProc(int nCode, WPARAM wParam, LPARAM lParam)
{

    if (nCode < 0 || nCode != HC_ACTION)
        return CallNextHookEx(g->KeyboardHook, nCode, wParam, lParam);
    
    WORD keyFlags = HIWORD(lParam);

    if ((wParam == VK_INSERT) && (keyFlags & KF_UP)) {
        // the key is up
    }

}