Timer t = new Timer();
        private void button1_Click(object sender, EventArgs e)
        {
            t.Interval = 2000;//2秒刷一次
            t.Enabled = true;//开始执行
            t.Tick += new EventHandler(t_Tick);//timer的代码
        }

        void t_Tick(object sender, EventArgs e)
        {
            this.Refresh();//刷新
              //MessageBox.Show("刷新了一次");
            t.Enabled = true;//重新调用代码，让它自动执行这段语句
        }