windows – 使用KBDLLHOOKSTRUCT确定第一次按键

BOOL wasDown;

LRESULT CALLBACK LowLevelKeyboardProc(int nCode,WPARAM wParam,LPARAM lParam) {
    if (nCode == HC_ACTION) {
        LPKBDLLHOOKSTRUCT key = (LPKBDLLHOOKSTRUCT) lParam;
        if (key->vkCode == VK_SOMETHING) {
            switch (wParam) {
                case WM_KEYDOWN:
                case WM_SYSKEYDOWN:
                    if (!wasDown) {
                        // Processing on first key down
                        wasDown = true;
                    }
                    break;
                case WM_KEYUP:
                case WM_SYSKEYUP:
                    // Processing on key up
                    wasDown = falSE;
                    break;
            }
    }
    return CallNextHookEx(NULL,nCode,wParam,lParam);
}

wasDown = GetAsyncKeyState(VK_SOMETHING) < 0;
hHook = SetWindowsHookEx(WH_KEYBOARD_LL,LowLevelKeyboardProc,hInstance,0);

当然,这段代码只能用于一个键.您可以使用一组标志来执行多个键.根据您的应用程序,如果您希望在设置挂钩后第一次按下,您还可以无条件地将标志设置为false.