如何无休止地检查是否按下了键
本文关键字:是否 检查 无休止 | 更新日期: 2023-09-27 18:30:20
我正在制作一个小程序,显示数字锁定或Capslock是打开还是关闭(因为我的笔记本电脑没有这些LED,所以我知道做这样的东西会很有趣)。我试图实现的是,如果按下或不按下键,文本会发生变化。到目前为止,我所拥有的是程序显示它们在自行运行程序之前是打开还是关闭。如何使程序对更改做出反应?
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace WindowsFormsApplication3
{
public partial class Form1 : Form
{
[DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true, CallingConvention = CallingConvention.Winapi)]
public static extern short GetKeyState(int keyCode);
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
looper();
}
public void looper()
{
cLock_check();
nLock_check();
sLock_check();
}
public void cLock_check()
{
bool CapsLock = (((ushort)GetKeyState(0x14)) & 0xffff) != 0;
if (CapsLock)
lbl_cLock_onOff.Text = "ON";
else
lbl_cLock_onOff.Text = "OFF";
}
public void nLock_check()
{
bool NumLock = (((ushort)GetKeyState(0x90)) & 0xffff) != 0;
if (NumLock)
lbl_nLock_onOff.Text = "ON";
else
lbl_nLock_onOff.Text = "OFF";
}
public void sLock_check()
{
bool ScrollLock = (((ushort)GetKeyState(0x91)) & 0xffff) != 0;
if (ScrollLock)
lbl_sLock_onOff.Text = "ON";
else
lbl_sLock_onOff.Text = "OFF";
}
}
}
应实现全局键盘挂钩,如本文中所述。将vkCode
与VK_NUMLOCK
、VK_CAPITAL
和VK_SCROLL
进行比较,并调用相关的更新函数。
创建一个计时器对象,给它一个合理的间隔(对于大多数"响应式"UI 问题,300 毫秒是合适的),并设置 Tick 处理程序以调用 looper
方法:
Timer checkState;
public Form1()
{
InitializeComponent();
checkState = new Timer { Interval = 300};
checkState.Tick += (o,e) => looper();
chechState.Start();
}