C#摇奖程序

private void Form1_Load(object sender, EventArgs e)
        {
            //取消跨线层访问控件的判断
            Control.CheckForIllegalCrossThreadCalls = false;
        }

        //声明一外bool变量用于控制随机数方法
        bool bl = false;
        private void button1_Click(object sender, EventArgs e)
        {
            //判读方是否在进运行
            if (bl == false)
            {
                bl = true;
                button1.Text = "停止";
                //做一个新线层，让他去做随机数的方法
                Thread trd = new Thread(PlayGame);
                trd.Start();

            }
            else
            {
                button1.Text = "开始";
                bl = false;

            }

        }

        //做一个随机数的方法
        private void PlayGame()
        {
            Random rm = new Random();
            while (bl)
            {

                //将随机数赋值给三个label控件

                label1.Text =rm.Next(, ).ToString();

                label2.Text = rm.Next(, ).ToString();

                label3.Text = rm.Next(, ).ToString();

            }

            if (label1.Text == label2.Text || label1.Text == label3.Text || label2.Text == label3.Text)
            {
                MessageBox.Show("中奖了");
            }
            else
            {
                MessageBox.Show("很可惜，没中奖");
            }
        }