private void startChange()
        {
            Thread threadChange = new Thread(new ThreadStart(changeLight));
            threadChange.Start();        }        private void changeLight()
        {
            bool light = true;
            while (light)
            {
                if (zuol1.BackColor == Color.White)
                {
                    zuol1.BackColor = Color.Green;
                    for (int i = 50000; i > 0; i--)
                    {                    }
                }
                else if (zuol1.BackColor == Color.Green)
                {
                    zuol1.BackColor = Color.Red;
                    for (int i = 50000; i > 0; i--)
                    {                    }
                }
                else
                {
                    zuol1.BackColor = Color.White;
                    for (int i = 50000; i > 0; i--)
                    {                    }
                }
            }
        }        private void button2_Click(object sender, EventArgs e)
        {
            startChange();

这样做还是不行啊 到底怎么回事呢 求指教