InputExtension.cs

using System.Runtime.InteropServices;
using UnityEngine;

public class KeyExtension
{

#if PLATFORM_STANDALONE_WIN

    [DllImport("user32.dll")]
    public static extern short GetKeyState(int key);

    const int VK_CAPITAL = 0x14;
    const int VK_NUMLOCK = 0x90;
    const int VK_SCROLL = 0x91;

    public static bool IsCapsLockOn()
    {
        return (GetKeyState(VK_CAPITAL) & 0xffff) != 0;
    }

    public static bool IsNumLockOn()
    {
        return (GetKeyState(VK_NUMLOCK) & 0xffff) != 0;
    }

    public static bool IsScrollLockOn()
    {
        return (GetKeyState(VK_SCROLL) & 0xffff) != 0;
    }

#else

    public static bool IsCapsLockOn()
    {
        return KeyValue(KeyCode.CapsLock);
    }

    public static bool IsNumLockOn()
    {
        return KeyValue(KeyCode.Numlock);
    }

    public static bool IsScrollLockOn()
    {
        return KeyValue(KeyCode.ScrollLock);
    }

#endif

    public static bool KeyValue(KeyCode keyCode)
    {
        if (Application.isPlaying)
        {
            return (Input.GetKey(keyCode));
        }
        else
        {
            return (Event.current.keyCode == keyCode);
        }
    }

}