The following code will allow you to turn on the numlock key upon startup. Can’t credit anyone as i’m not sure where it came from but it does work 100%
using System;
using System.Runtime.InteropServices;
class SetNumlockKeyOn
{
[StructLayout(LayoutKind.Sequential)]
public struct INPUT
{
internal int type;
internal short wVk;
internal short wScan;
internal int dwFlags;
internal int time;
internal IntPtr dwExtraInfo;
int dummy1;
int dummy2;
internal int type1;
internal short wVk1;
internal short wScan1;
internal int dwFlags1;
internal int time1;
internal IntPtr dwExtraInfo1;
int dummy3;
int dummy4;
}
[DllImport(“user32.dll”)]
static extern int SendInput(uint nInputs, IntPtr pInputs, int cbSize);
public static void SetNumlockOn()
{
const int mouseInpSize = 28;//Hardcoded size of the MOUSEINPUT tag !!!
INPUT input = new INPUT();
input.type = 0x01; //INPUT_KEYBOARD
input.wVk = 0x90; //VK_NUMLOCK
input.wScan = 0;
input.dwFlags = 0; //key-down
input.time = 0;
input.dwExtraInfo = IntPtr.Zero;
input.type1 = 0x01;
input.wVk1 = 0x90;
input.wScan1 = 0;
input.dwFlags1 = 2; //key-up
input.time1 = 0;
input.dwExtraInfo1 = IntPtr.Zero;
IntPtr pI = Marshal.AllocHGlobal(mouseInpSize * 2);
Marshal.StructureToPtr(input, pI, false);
int result = SendInput(2, pI, mouseInpSize); //Hardcoded size of the MOUSEINPUT tag !!!
//if (result == 0 || Marshal.GetLastWin32Error() != 0)
// Console.WriteLine(Marshal.GetLastWin32Error());
Marshal.FreeHGlobal(pI);
}
}
Just noticed that this will turn it on if it’s already off and vice versa SOOOOOOOOOO if you want to put a check in there, add the following code:
[DllImport(“user32.dll”)]
internal static extern short GetKeyState(int keyCode);
bool NumLock = (GetKeyState((int)System.Windows.Forms.Keys.NumLock)) != 0; // check if key is already down
if (!NumLock) // if already down dont proceed
{
// do you stuff
}