using System;

 using System.Collections.Generic;

 using System.ComponentModel;

 using System.Data;

 using System.Drawing;

 using System.Linq;

 using System.Text;

 using System.Threading;

 using System.Threading.Tasks;

 using System.Windows.Forms;

 namespace ListBoxAutoScroll

 {

     public partial class Form1 : Form

     {

         Thread[] threadArr = new Thread[];

         bool scroll = false;

         object obj = new object();

         delegate void AddItemCallback(string text);

         public Form1()

         {

             InitializeComponent();

         }

         private void btnStart_Click(object sender, EventArgs e)

         {

             listBoxMsg.Items.Clear();

             for (int i = ; i < threadArr.Length; i++)

             {

                 if (threadArr[i] == null || threadArr[i].ThreadState == ThreadState.Aborted || threadArr[i].ThreadState == ThreadState.Stopped)

                 {

                     threadArr[i] = new Thread(new ThreadStart(() => AddData(i)));

                     threadArr[i].Name = i.ToString();

                 }

                 threadArr[i].Start();

             }

         }

         public void AddData(int i)

         {

             while (true)

             {

                 AddItem("ListBox中添加【第" + i.ToString() + "项】");

                 Thread.Sleep();

             }

         }

         private void AddItem(string text)

         {

             if (this.listBoxMsg.TopIndex == this.listBoxMsg.Items.Count - (int)(this.listBoxMsg.Height / this.listBoxMsg.ItemHeight))

                 scroll = true;

             if (this.listBoxMsg.InvokeRequired)

             {

                 AddItemCallback d = new AddItemCallback(AddItem);

                 this.Invoke(d, new object[] { text });

             }

             else

             {

                 this.listBoxMsg.Items.Add(text);

             }

             if (scroll)

                 this.listBoxMsg.TopIndex = this.listBoxMsg.Items.Count - (int)(this.listBoxMsg.Height / this.listBoxMsg.ItemHeight);

         }

         private void btnStop_Click(object sender, EventArgs e)

         {

             for (int i = ; i < threadArr.Length; i++)

             {

                 if (threadArr[i] != null && threadArr[i].ThreadState != ThreadState.Stopped && threadArr[i].ThreadState != ThreadState.Aborted)

                 {

                     threadArr[i].Abort();

                 }

             }

         }

     }

 }