C# 线程更新 UI

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;

namespace WindowsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
UpdateUI();

Thread workthread = new Thread(new ThreadStart(this.DoSomething));

workthread.Start();
}

private delegate void InvokeMethodDelegate();

void DoSomething()
{
System.Threading.Thread.Sleep(5 * 1000);

this.Invoke(new InvokeMethodDelegate(this.UpdateUI));
}

void UpdateUI()
{
textBox1.Text = textBox1.Text + DateTime.Now.ToLongTimeString() + "\r\n";
}
}
}