请教这样的代码，可以使用委托来更新控件内容吗

请问这样的代码，可以使用委托来更新控件内容吗？

C# code

public class Test    {        int _index = 0;        Thread _thread;        public int Index        {            get { return _index; }            set { _index = value; }        }        public Thread Thread        {            get { return _thread; }            set { _thread = value; }        }        public void Run()        {            string result = DateTime.Now.ToString("HH:mm:ss:fff") + "  " + _thread.ManagedThreadId.ToString("00") + " is " + _thread.IsAlive.ToString() + ":" + _index.ToString();            try            {                File.AppendAllText("result.txt", result + "\r\n");            }            catch (Exception ex)            {                File.AppendAllText("result_failed.txt", result + "    " + ex.Message + "\r\n");            }            //请问在这里如何给textBox1.Text赋值 result 呢：（            //想实现每一个进程执行完后都在textBox1.Text中输出 result 结果        }    }

C# code

using System;using System.IO;using System.Threading;using System.Windows.Forms;namespace 多线程操作FORM{    public delegate void ChangeTextBox(string text);    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private void button1_Click(object sender, EventArgs e)        {            for (int i = 0; i < 24; i++)            {                Test test = new Test();                test.Index = i;                test.WorkCompleted += new EventHandler(test_WorkCompleted);                Thread thread = new Thread(new ThreadStart(test.Run));                thread.IsBackground = true;                test.Thread = thread;                thread.Start();                //Thread.Sleep(1);            }            //textBox1.Text = "完成";        }        void test_WorkCompleted(object sender, EventArgs e)        {            int i = ((Test)sender).Index;            if (this.InvokeRequired)            {                this.Invoke(new ChangeTextBox(ChangeTextBoxMethod), i.ToString());            }            else            {                ChangeTextBoxMethod(i.ToString());            }        }        private void ChangeTextBoxMethod(string value)        {            textBox1.Text += string.Format("Work {0} done.{1}", value, Environment.NewLine);        }    }    public class Test    {        int _index = 0;        Thread _thread;        public event EventHandler WorkCompleted;        public int Index        {            get { return _index; }            set { _index = value; }        }        public Thread Thread        {            get { return _thread; }            set { _thread = value; }        }        public void Run()        {            string result = DateTime.Now.ToString("HH:mm:ss:fff") + "  " + _thread.ManagedThreadId.ToString("00") + " is " + _thread.IsAlive.ToString() + ":" + _index.ToString();            try            {                File.AppendAllText("result.txt", result + "\r\n");            }            catch (Exception ex)            {                File.AppendAllText(string.Format("result{0}_failed.txt", Index.ToString()), result + "    " + ex.Message + "\r\n");            }            if (WorkCompleted != null)            {                WorkCompleted(this, EventArgs.Empty);            }            //请问在这里如何给textBox1.Text赋值 result 呢：（            //想实现每一个进程执行完后都在textBox1.Text中输出 result 结果        }    }}