c# - 如何在 C# 中以编程方式检查和切换 Num-Lock？

Question

我想以编程方式检查值，并能够切换数字锁定。在 C# 中执行此操作的最简单方法是什么？

原因是我想在程序启动时验证 num-lock 是否为“ON”。

谢谢

Answer 1

检查 How to programmatically turn on the Numlock Key

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);
}