c++ - WH_KEYBOARD_LL 不适用于常规字母和数字

Question

我SetWindowsHookExA(WH_KEYBOARD_LL, HookCallback, GetModuleHandleA(NULL), 0);用来设置一个全局钩子来捕获击键，但结果很奇怪。
回调函数可以在我按下“Enter”、“Tab”、“Shift”、“Ctrl”等具有虚拟键码的“特殊”键时执行，而当我按下时无法捕获击键常规的字母和数字。
我对此感到困惑，谁能告诉我原因？

#include <Windows.h>
#include <iostream>
using namespace std;

HHOOK keyboardHook = 0;

LRESULT CALLBACK HookCallback(int code, WPARAM wParam, LPARAM lParam)
{
    KBDLLHOOKSTRUCT *ks = (KBDLLHOOKSTRUCT*)lParam;
    cout<< "[TEST] " << ks->vkCode << endl;

    return CallNextHookEx(0, code, wParam, lParam);
}

int main()
{
    keyboardHook = SetWindowsHookExA(WH_KEYBOARD_LL, HookCallback, GetModuleHandleA(NULL), 0);
    if (keyboardHook == 0)
    {
        cout << "failed" << endl;
        return -1;
    }
    cout << "ok" << endl;

    MSG msg;
    while(GetMessage(&msg, NULL, 0, 0)){
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    UnhookWindowsHookEx(keyboardHook);


    return 0;
}