Using RegisterHotKey with number pad values not working? - visual-c++

Question

I have some constants:
constexpr int MonitorDisplay1 = 100;
constexpr int MonitorDisplay2 = 200;
constexpr int MonitorDisplay3 = 400;
constexpr int MonitorDisplay4 = 500;
constexpr int MonitorDisplay1KeyPad = 101;
constexpr int MonitorDisplay2KeyPad = 201;
constexpr int MonitorDisplay3KeyPad = 401;
constexpr int MonitorDisplay4KeyPad = 501;
I have an OnCreate where I setup the hot keys:
int CCenterCursorOnScreenDlg::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
if (__super::OnCreate(lpCreateStruct) == -1)
return -1;
auto RegisterAppHotkey = [hAppWnd = GetSafeHwnd()](const int nHotKeyID, UINT vk)->bool
{
if (!::RegisterHotKey(hAppWnd, nHotKeyID, MOD_CONTROL | MOD_SHIFT, vk))
{
auto const ec = ::GetLastError();
auto const err_msg = std::format(L"RegisterHotKey failed (error: {})\n",
ec);
AfxMessageBox(err_msg.c_str());
return false;
}
return true;
};
if (m_monitors.rcMonitors.size() > 0)
{
if (!RegisterAppHotkey(MonitorDisplay1, '1'))
{
return -1;
}
if (!RegisterAppHotkey(MonitorDisplay1KeyPad, VK_NUMPAD1))
{
return -1;
}
}
if (m_monitors.rcMonitors.size() > 1)
{
if (!RegisterAppHotkey(MonitorDisplay2, '2'))
{
return -1;
}
if (!RegisterAppHotkey(MonitorDisplay2KeyPad, VK_NUMPAD2))
{
return -1;
}
}
if (m_monitors.rcMonitors.size() > 2)
{
if (!RegisterAppHotkey(MonitorDisplay3, '3'))
{
return -1;
}
if (!RegisterAppHotkey(MonitorDisplay3KeyPad, VK_NUMPAD3))
{
return -1;
}
}
if (m_monitors.rcMonitors.size() > 3)
{
if (!RegisterAppHotkey(MonitorDisplay4, '4'))
{
return -1;
}
if (!RegisterAppHotkey(MonitorDisplay4KeyPad, VK_NUMPAD4))
{
return -1;
}
}
return 0;
}
Previously I just had the 4 hotkeys for 1 / 2 / 3 and 4. They still work. I tried to add new hotkeys for for the number pad on the keyboard, but they are not working.
My OnHotKey handler:
void CCenterCursorOnScreenDlg::OnHotKey(UINT nHotKeyId, UINT nKey1, UINT nKey2)
{
if (nHotKeyId == MonitorDisplay1 || nHotKeyId == MonitorDisplay1KeyPad)
{
CenterCursorOnMonitor(0);
}
else if (nHotKeyId == MonitorDisplay2 || nHotKeyId == MonitorDisplay2KeyPad)
{
CenterCursorOnMonitor(1);
}
else if (nHotKeyId == MonitorDisplay3 || nHotKeyId == MonitorDisplay3KeyPad)
{
CenterCursorOnMonitor(2);
}
else if (nHotKeyId == MonitorDisplay4 || nHotKeyId == MonitorDisplay4KeyPad)
{
CenterCursorOnMonitor(3);
}
__super::OnHotKey(nHotKeyId, nKey1, nKey2);
}
But the number pad versions are not working. Why?
I am unregistering all 8 hotkeys, and num-lock is on. I get no warnings when registering.

Answer 1

This article explains List of Keys (Keyboard, Mouse and Joystick):
Because I was using CTRL + SHIFT, then the meaning of the 4 numeric keys was changing:
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It made sense to change my hotkeys to CTRL + ALT instead to avoid this issue.