利用多线程写一个摇奖机小程序

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 yaojiangji
{
    public partial class Form1 : Form
    {
        private List<Label> lbList = new List<Label>();
        private bool isRunning = false;
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            for (int i = 0; i <6; i++)
            {
                Label lb = new Label();
                lb.Text = "0";
                lb.AutoSize = true;
                lb.Location = new Point(60*i+60,100);
                this.Controls.Add(lb);
                lbList.Add(lb);
                
            }

        }

        private void btnStartOrStop_Click(object sender, EventArgs e)
        {
            if (isRunning == false)
            {
                isRunning = true;
                btnStartOrStop.Text = "停止";
                Thread thread = new Thread(() =>
                {
                    Random r = new Random();
                    while (isRunning)
                    {
                        foreach (var item in lbList)
                        {
                            string str = r.Next(0, 10).ToString();
                            if (item.InvokeRequired)
                            {
                                item.Invoke(new Action<string>(s => { item.Text = s; }), str);
                            }
                            else
                            {
                                item.Text = str;
                            }

                        }
                        Thread.Sleep(50);

                    }

                });
                thread.IsBackground = true;
                thread.Start();
            }
            else
            {
                isRunning = false;
                btnStartOrStop.Text = "开始";

            }
        }
    }
}