双色球生成器

public partial class Form1 : Form
    {
        private bool flag = true;
        delegate void SetTextDelegate(Label label, string text);
        private Label[] labels;
        private Font font;
        public Form1()
        {
            InitializeComponent();
        }
        /// <summary>
        /// 制造号码
        /// </summary>
        private int[] MakeNums()
        {
            int[] arr = new int[7];
            Random rand = new Random();
            Hashtable ht = new Hashtable();
            //产生不重复的随机数
            int key = 0;
            while (ht.Count <= 6)
            {
                int val = rand.Next(1, 34);
                if (!ht.ContainsValue(val))
                { ht.Add(key, val); key++; }
            }
            //得到随机数
            for (int i = 0; i < 6; i++)
            {
                arr[i] = (int)ht[i];
            }
            //冒泡排序
            int temp;
            for (int outer = 5; outer >= 0; outer--)
            {
                for (int inner = 0; inner <= outer - 1; inner++)
                {
                    if (arr[inner] > arr[inner + 1])
                    {
                        temp = arr[inner];
                        arr[inner] = arr[inner + 1];
                        arr[inner + 1] = temp;
                    }
                }
            }
            //制造蓝色球
            arr[6] = rand.Next(1, 17);
            return arr;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (button1.Text == "start")
            {
                flag = true;
                button1.Text = "stop";
                ThreadStart TStart = new ThreadStart(Start);
                Thread thread = new Thread(TStart);
                thread.Start();
            }
            else
            {
                flag = false;
                button1.Text = "start";
            }
        }

        private void Start()
        {
            while (flag)
            {
                PrintNum();
                Thread.Sleep(88);
            }
        }
        private void PrintNum()
        {
            int[] arr = MakeNums();
            for (int i = 0; i < 7; i++)
            {
                Invoke(
                    new MethodInvoker(delegate()
                               {
                                   SetText(labels[i], arr[i].ToString());
                               }
                               ));
            }

            //for (int i = 0; i < 7; i++)
            //{
            //    SetTextDelegate mydelegate = new SetTextDelegate(SetText);
            //    try
            //    {
            //        Invoke(mydelegate, labels[i], arr[i].ToString());
            //    }
            //    catch { return; }
            //}
        }
        private void SetText(Label label, string text)
        {
            label.Text = text;
            label.TextAlign = ContentAlignment.MiddleCenter;
            label.Font = font;
            if (label.Name == "label7")
            { label.ForeColor = Color.Blue; }
            else
            { label.ForeColor = Color.Red; }
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            labels = new Label[] { label1, label2, label3, label4, label5, label6, label7 };
            font = new Font("Arial Black", 36);
        }

    }