How can I find the state of NumLock, CapsLock and ScrollLock in .NET?

Question

How can I find the state of NumLock, CapsLock and ScrollLock keys in .NET?

Answer 1

Import the WinAPI function GetKeyState:

[DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true, CallingConvention = CallingConvention.Winapi)]
public static extern short GetKeyState(int keyCode);

And then you can use it like this:

bool CapsLock = (((ushort)GetKeyState(0x14)) & 0xffff) != 0;
bool NumLock = (((ushort)GetKeyState(0x90)) & 0xffff) != 0;
bool ScrollLock = (((ushort)GetKeyState(0x91)) & 0xffff) != 0;

It is for framework 1.1. For framework 2.0 (and later) you can use:

Control.IsKeyLocked