C#线程问题 在线等。。。。。

Question

利用线程让label显示当前时间
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        string s;
        public Form1(string s1)
        {
            s = s1;
        }
        public void showtime()
        {            s = DateTime.Now.ToLongTimeString();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            Form1 f = new Form1(label1.Text);
            Thread th = new Thread(new ThreadStart(f.showtime));
            th.Start();
            th.Join();
        }
    }
}点了按钮 label没反应 求解 求解 在线等！！！

Answer 1

public partial class Form1 : Form
    {
        private delegate void FlushClient();
        public Form1()
        {
            InitializeComponent();
        }
        
        private void button1_Click(object sender, EventArgs e)
        {            Thread th = new Thread(new ThreadStart(ThreadFunction));
            th.Start();
            
        }
       
        private void ThreadFunction()
        {
            if (this.label1.InvokeRequired)//等待异步
            {
                FlushClient fc = new FlushClient(ThreadFunction);
                this.Invoke(fc);//通过代理调用刷新方法
            }
            else
            {
               
                this.label1.Text = DateTime.Now.ToString();
            }
        }
    }

Answer 2

你的线程干什么Join()呢？Join就挂起了。另外，为了保证UI的线程安全，必须用Delegate,Invoke一下。

Answer 3

Timer timer1;
  this.timer1.Interval = 1000;
  this.timer1.Tick += new System.EventHandler(this.timer1_Tick);  private void timer1_Tick(object sender, EventArgs e)
  {
  timebox.Text = DateTime.Now.ToString();   
  }