SetWindowsHookEx - difference between VK_LSHIFT and “Search” keyboard button

问题

I use SetWindowsHookEx to catch keyboard events

SetWindowsHookEx(WH_KEYBOARD_LL, HookCallback, NULL, 0)

Here is HookCallback

LRESULT __stdcall HookCallback(int nCode, WPARAM wParam, LPARAM lParam)
{
    if (nCode >= 0)
    {
        // the action is valid: HC_ACTION.
        if (wParam == WM_KEYDOWN)
        {
            kbdStruct = *((KBDLLHOOKSTRUCT*)lParam);
            printf("%ld\n", kbdStruct.vkCode);
        }
    }
}

When press "left shift" output is

when press "search" button (button with loupe icon on notebooks) output is

160
91
132

How to check if "left shift" or "search" button is pressed inside HookCallback ?

回答1:

160 is VK_LSHIFT, 91 is VK_LWIN, and 132 is VK_F21. See Virtual-Key Codes. The only standardized Search key is VK_BROWSER_SEARCH, so clearly your keyboard manufacturer is using a non-standard key for its Search key.

You need to remember the keys you see from one event to the next as needed, eg:

bool LeftShiftIsDown = false;
bool LeftWinIsDown = false;
bool F21IsDown = false;
bool SearchIsDown = false;

LRESULT __stdcall HookCallback(int nCode, WPARAM wParam, LPARAM lParam)
{
    if (nCode == HC_ACTION)
    {
        KBDLLHOOKSTRUCT *kbdStruct = (KBDLLHOOKSTRUCT*) lParam;
        if (wParam == WM_KEYDOWN)
        {
            printf("%ld is down\n", kbdStruct->vkCode);
            switch (kbdStruct->vkCode)
            {
                case VK_LSHIFT:
                    LeftShiftIsDown = true;
                    break;
            case VK_LWIN:
                    LeftWinIsDown = true;
                    break;
            case VK_F21:
                    F21IsDown = true;
                    break;
            }

            if (LeftShiftIsDown && LeftWinIsDown && F21IsDown)
            {
                if (!SearchIsDown)
                {
                    SearchIsDown = true;
                    printf("Search is down\n");
                }
            }
        }
        else if (wParam == WM_KEYUP)
        {
            printf("%ld is up\n", kbdStruct->vkCode);
            switch (kbdStruct->vkCode)
            {
                case VK_LSHIFT:
                    LeftShiftIsDown = false;
                    break;
                case VK_LWIN:
                    LeftWinIsDown = false;
                    break;
                case VK_F21:
                    F21IsDown = false;
                    break;
            }

            if (!(LeftShiftIsDown && LeftWinIsDown && F21IsDown))
            {
                if (SearchIsDown)
                {
                    SearchIsDown = false;
                    printf("Search is up\n");
                }
            }
        }
    }
    return CallNextHookEx(0, nCode, wParam, lParam);
}

来源：https://stackoverflow.com/questions/59800732/setwindowshookex-difference-between-vk-lshift-and-search-keyboard-button

标签

windows

winapi