ListBox自动滚动并限制显示条数

1、实现功能
限制ListBox显示的最大条数；
ListBox自动滚动，显示最新行；
2、C#代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using static System.Windows.Forms.VisualStyles.VisualStyleElement.ProgressBar;namespace ListBoxApp
{public partial class Form1 : Form{Timer timer;bool isRun = false;int count = 0;int MAX_COUNT = 20;string filename = "";/// <summary>/// 构造函数/// </summary>public Form1(){InitializeComponent();}/// <summary>/// 窗体加载/// </summary>/// <param name="sender"></param>/// <param name="e"></param>private void Form1_Load(object sender, EventArgs e){timer = new Timer();timer.Interval = 500;timer.Tick += Timer_Tick;timer.Start();}/// <summary>/// 定时处理/// </summary>/// <param name="sender"></param>/// <param name="e"></param>private void Timer_Tick(object sender, EventArgs e){if (isRun){string str = $"No. {count} item";ListBoxSaveAndAdd(filename,listBox1, str, MAX_COUNT);count++;}}/// <summary>/// 测试开启和停止/// </summary>/// <param name="sender"></param>/// <param name="e"></param>private void btStart_Click(object sender, EventArgs e){if (btStart.Text.Equals("开始")){btStart.Text = "停止";listBox1.Items.Clear();filename = Path.Combine(Environment.CurrentDirectory, "f"+DateTime.Now.ToString("yyyyMMdd_HHmmssFFF")+".txt");count = 0;isRun = true;}else{btStart.Text = "开始";isRun = false;}}#region 处理算法/// <summary>/// 数据保存和ListBox添加/// </summary>/// <param name="filename"></param>/// <param name="listBox"></param>/// <param name="text"></param>/// <param name="maxCount"></param>public static void ListBoxSaveAndAdd(string filename, ListBox listBox, string text, int maxCount){FileStreamWriter(filename, text);ListBoxScrollAddCross(listBox, text, maxCount);}/// <summary>/// 文件保存/// </summary>/// <param name="filename"></param>/// <param name="content"></param>public static void FileStreamWriter(string filename, string content){using (StreamWriter sw = new StreamWriter(filename, true)){sw.WriteLine(content);}}/// <summary>/// listBox跨域处理/// </summary>/// <param name="listBox"></param>/// <param name="text"></param>/// <param name="maxCount"></param>public static void ListBoxScrollAddCross(ListBox listBox, string text, int maxCount){if (listBox.InvokeRequired){MethodInvoker mi = delegate (){ListBoxScrollAdd(listBox, text, maxCount);};listBox.Invoke(mi);}else{ListBoxScrollAdd(listBox, text, maxCount);}}/// <summary>/// listBox添加/// </summary>/// <param name="listBox"></param>/// <param name="text"></param>/// <param name="maxCount"></param>public static void ListBoxScrollAdd(ListBox listBox, string text, int maxCount){listBox.Items.Add(text);if (listBox.Items.Count > maxCount){listBox.Items.RemoveAt(0);}listBox.TopIndex = listBox.Items.Count - (int)(listBox.Height / listBox.ItemHeight);}#endregion}
}